Electro-thermal conversion phase change heat storage device

Abstract

The utility model belongs to the technical field of heat storage, and relates to an electro-thermal conversion phase change heat storage device which comprises a packaging module and a phase change medium storage area, the phase change medium storage area is arranged in the packaging module and used for containing a phase change medium, and the phase change medium generates steam through phase change; the heat storage material layer is arranged between the phase change medium storage area and the packaging module; a phase change medium feeding system; a heating system; a heat release system; and the phase change medium feeding system and the heat release system are communicated with the phase change medium storage area. The phase change medium is heated through the heat storage material layer to generate steam, the steam is collected and discharged at the required flow and pressure through the heat release system, the heating and heat release processes are automatically switched through the thermocouple, the pressure gauge, the gas flow meter and the control system according to the temperature and pressure, heat charging and heat release are intelligently controlled, and the heating efficiency is improved. The heat release process and the temperature of the temperature field of the heat storage material layer are integrally stable, and efficient and stable heat energy storage and release are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of heat storage and relates to an electrothermal conversion phase change heat storage device. Background Art

[0002] At present, renewable energy sources such as wind energy and solar energy are developing rapidly year by year. In addition, the electricity consumption of the whole society is rising year by year, and the peak-to-valley difference of power grid electricity consumption is increasing day by day. The power grid has an increasingly strong demand for low-cost, long-life energy storage technology. According to the quality of energy storage, the current energy storage technology can be simply divided into electrical storage, potential energy storage and heat storage. Among them, electrical storage can be divided into lithium batteries, liquid flow batteries, supercapacitors, etc., potential energy storage can be divided into pumped storage, compressed air, flywheels, etc., and heat storage can be divided into solid heat storage, molten salt heat storage, thermochemical storage, etc.

[0003] Molten salt heat storage systems are currently widely used in solar thermal power stations, clean heating and other scenarios. They have the advantages of high heat storage temperature and long service life, but this technical solution has a great demand for molten salt heat storage media. When the heat storage temperature difference is 200°C and the heat storage capacity is 80MWh, the demand for conventional molten salt is about 1,300 tons. The prices of molten salts such as potassium nitrate, sodium nitrate, and calcium nitrate are greatly affected by the international market and raw materials. When the cost of raw materials such as potassium chloride and nitric acid rises sharply, the price of molten salt will increase significantly, which will directly affect the investment cost and implementation progress of the project.

[0004] The solid heat storage system is a simple and easy heat storage technology. Its basic principle is to transfer heat to solid heat storage materials such as concrete or refractory bricks for storage. When heat release is required, heat is exchanged with the solid heat storage material through the heat transfer medium. The heat storage materials of the solid heat storage system are easy to obtain and have stable prices. The raw materials do not rely on imports and are insensitive to market price fluctuations.

[0005] However, the disadvantage of the solid heat storage system is that the charging and discharging process is unstable. As heat is continuously released during the heat release process, the temperature of the solid heat storage material temperature field drops as a whole, resulting in a continuous decrease in the outlet temperature of the heat transfer medium during the heat release process, which affects the stability of the subsequent heat utilization system. Summary of the invention

[0006] The object of the present invention is to provide an electrothermal conversion phase change heat storage device for realizing efficient and stable thermal energy storage and release.

[0007] The present invention provides an electrothermal conversion phase change heat storage device, comprising:

[0008] Container module,

[0009] A phase change medium storage area, the phase change medium storage area is placed inside the container module, the phase change medium storage area is used to contain a phase change medium, and the phase change medium undergoes phase change to generate steam;

[0010] A heat storage material layer, wherein the heat storage material layer is disposed between the phase change medium storage area and the container module;

[0011] A phase change medium feeding system, used for inputting phase change medium into the phase change medium storage area;

[0012] A heating system, wherein the heating system is used to heat the heat storage material layer;

[0013] A heat release system, the heat release system is used to release steam generated by the phase change of the phase change medium;

[0014] The phase change medium feeding system and the heat release system are in communication with the phase change medium storage area.

[0015] In some embodiments, the phase change medium storage area is connected to a thermocouple and a pressure gauge for monitoring the temperature and pressure in the phase change medium storage area, respectively.

[0016] In some embodiments, the heat storage material layer (6) is amorphous sand or powdered solid heat storage material; preferably, the heat storage material layer (6) is at least one of powdered phosphogypsum or iron tailings.

[0017] In some embodiments, the heating system includes a plurality of fin-type electric heaters, which are pre-buried in the heat storage material layer and connected to an external power source for heating the heat storage material layer to provide heat.

[0018] In some embodiments, a plurality of the finned electric heaters are evenly and staggeredly distributed in the heat storage material layer.

[0019] In some embodiments, the phase change medium feeding system includes a phase change medium delivery pipe and a phase change medium feed pump, wherein one end of the phase change medium delivery pipe is installed on the phase change medium storage area and is connected to the internal space of the phase change medium storage area, and the other end extends to the outside of the container module, and is used to transport the phase change medium outside the container module to the phase change medium storage area. The phase change medium feed pump is installed on the phase change medium delivery pipe, and is used to control the delivery of the phase change medium.

[0020] In some embodiments, the flow rate of the phase change medium in the phase change medium delivery pipe is 10 to 25 m / s. 3 / h.

[0021] In some embodiments, the heat release system includes an exhaust valve and a heat release pipe, one end of the heat release pipe is fixed to the phase change medium storage area and connected to the interior of the phase change medium storage area, and the other end extends to the outside of the container module, and the exhaust valve is installed on the phase change medium storage area and connected to the heat release pipe.

[0022] In some embodiments, the heat release system further comprises a gas flow meter installed on the heat release pipe.

[0023] In some embodiments, the heat storage device further includes a control system, wherein the control system includes a control panel, and the control panel is electrically connected to the phase change medium feed pump, the thermocouple, and the pressure gauge.

[0024] In summary, the present application includes at least one of the following beneficial technical effects:

[0025] The phase change medium is heated by the heat storage material layer to cause phase change and generate steam. The charging and releasing of heat is intelligently controlled according to the temperature and pressure of the phase change medium through thermocouples, pressure gauges, gas flow meters and control systems. The steam releases thermal energy and the temperature of the temperature field of the heat storage material layer is generally stable, realizing efficient and stable thermal energy storage and release. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic structural diagram of the electrothermal conversion phase change heat storage device of this embodiment;

[0027] Figure 2 Schematic diagram of the structure of the valve control system of this embodiment.

[0028] Figure numerals: 1. container module; 2. phase change medium storage area; 3. phase change medium delivery pipe; 4. phase change medium feed pump; 5. heat release pipe; 6. heat storage material layer; 7. fin-type electric heater; 8. control panel. DETAILED DESCRIPTION

[0029] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. However, it will be appreciated by those skilled in the art that in the embodiments of the present application, many technical details are proposed in order to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the present application can also be implemented. The division of the following embodiments is for the convenience of description, and the specific implementation of the present application should not be construed as any limitation, and the various embodiments can be combined with each other and quoted from each other without contradiction.

[0030] The following is a detailed description of an electrothermal conversion phase change heat storage device provided in this embodiment in conjunction with the accompanying drawings.

[0031] Reference Figure 1, an electrothermal conversion phase change heat storage device, including a container module 1, a phase change medium storage area 2, a phase change medium feeding system, a heat storage material layer 6, a heating system, a heat release system and a control system, the phase change medium storage area 2 is placed inside the container module 1, the heat storage material layer 6 is placed in the accommodation space formed between the phase change medium storage area 2 and the container module 1, the phase change medium feeding system connects the phase change medium storage area 2 with the outside of the container module 1, the heating system is arranged in the heat storage material layer 6, the heat release system connects the phase change medium storage area 2 with the outside of the container module 1, the control system is arranged outside the container module 1 and is electrically connected to the phase change medium feeding system and the heat release system, for controlling the conversion and release of thermal energy.

[0032] Reference Figure 1 , container module 1 is a standard 20GP container, used to accommodate and install other structures, and the internal dimensions of container module 1 are L*B*H=5.898*2.352*2.391mm.

[0033] The phase change medium storage area 2 is installed inside the container module 1. The phase change medium storage area 2 is a hollow tank for storing phase change medium. The phase change medium storage area 2 is provided with a phase change medium inlet and outlet, a thermocouple connection interface, and a pressure gauge connection interface. The phase change medium inlet is respectively connected to the phase change medium feeding system so as to transport the external phase change medium to the phase change medium storage area 2. The phase change medium outlet is connected to the heat release system to output the heat generated by the phase change of the phase change medium in the phase change medium storage area 2 for subsequent use.

[0034] The thermocouple link interface is connected to a thermocouple, which can directly measure the temperature of the phase change medium in the phase change medium storage area 2 after the phase change occurs, and then convert the temperature signal into a thermoelectric potential signal, which is converted into the temperature of the measured medium through an electrical instrument (secondary instrument). The pressure gauge link interface is connected to a pressure gauge to monitor the pressure in the phase change medium storage area 2.

[0035] The phase change medium feeding system includes a phase change medium delivery pipe 3 and a phase change medium feed pump 4. The size of the phase change medium delivery pipe 3 is DN50. One end of the phase change medium delivery pipe 3 is installed on the phase change medium storage area 2 and communicates with the internal space of the phase change medium storage area 2. The other end extends to the outside of the container module 1, and is used to transport the phase change medium outside the container module 1 to the phase change medium storage area 2. The phase change medium feed pump 4 can be a water pump, etc. The phase change medium feed pump 4 is installed on the end of the phase change medium delivery pipe 3 extending to the outside of the container module 1, and is used to control the delivery of the phase change medium. Its flow rate is 10 to 25m 3 / h, the power is 1.5Kw.

[0036] The heat release system includes an exhaust valve, a heat release pipe 5 and a gas flow meter. The exhaust valve is installed on the phase change medium storage area 2 and communicated with the heat release pipe 5 to control the steam entering the heat release pipe 5. One end of the heat release pipe 5 is fixed to the phase change medium storage area 2 and communicated with the inside of the phase change medium storage area 2, and the other end extends to the outside of the container module 1 to export the heat generated by the phase change of the phase change medium in the phase change medium storage area 2. The gas flow meter is installed on the heat release pipe 5 to monitor the steam flow in the heat release pipe 5.

[0037] The volume of the phase change medium storage area 2 is smaller than the container module 1, so that a space is formed between the phase change medium storage area 2 and the container module 1 for accommodating the heat storage material layer 6. The heat storage material layer 6 is an amorphous sand or powdered solid, such as powdered phosphogypsum or iron tailings, etc. The heat storage material layer 6 can be heated by solar energy or wind power generation to store heat and supply the energy required for the phase change of the phase change medium in the phase change medium storage area 2. Amorphous sand or powdered solid composite heat storage materials solve the problem that specific fixed solid shape heat storage materials such as bricks produce cracks, peeling, and collapse due to extreme cold and heat.

[0038] Reference Figure 1 The heating system includes a plurality of fin-type electric heaters 7, which are pre-buried in the heat storage material layer 6 and connected to an external power source, and are used to heat the heat storage material layer 6. The plurality of fin-type electric heaters 7 are evenly and staggeredly distributed in the heat storage material layer 6 to improve the uniformity of the temperature field of the heat storage material layer 6. In other embodiments, the heat storage material layer 6 can also be heated by other means such as photovoltaic power generation and wind power generation, and the fin-type electric heater 7 can also be other heating devices such as heating rods or resistance wires.

[0039] The phase change medium is pure water, which undergoes phase change when heated by the heat storage material layer 6, generating high-temperature steam which is transported to the outside of the container module 1 through the heat release pipe 5 and supplied to the steam turbine generator for power generation or civil hot water heating. It can also produce industrial steam and other uses.

[0040] Reference Figure 1-2 The control system includes a control panel 8, which is electrically connected to the phase change medium feed pump 4, the thermocouple, and the pressure gauge, and is used to adjust the flow and pressure of the phase change medium, thereby controlling the conversion and release of heat energy. The control panel 8 is used to adjust the temperature and pressure of the phase change medium to control the steam production, so that the parameters and flow of the steam in the heat release process are more stable. The constant temperature and constant pressure characteristics of the phase change medium in the phase change process are used to stabilize the heat release process and solve the problem of unstable heat release process. The control system is an intelligent control system that automatically switches the heating and heat release processes through temperature and pressure.

[0041] The implementation principle of this embodiment is: the control panel 8 controls the heating system to convert electrical energy into thermal energy to heat the heat storage material layer 6. The heat storage material layer 6 absorbs this part of the thermal energy and the temperature rises to store heat. When the thermocouple detects that the temperature rises to the set value, the control panel 8 controls the heating system to stop heating. At this time, the heat storage material layer 6 has stored the required thermal energy. When this part of the thermal energy is needed, the pure water required by the process is added to the phase change medium storage area 2 by the phase change medium delivery pipe 3 and the phase change medium feed pump 4. The heat storage material layer 6 after heat storage exchanges heat with the phase change medium, and the heated phase change medium is vaporized. The temperature and pressure of the phase change medium are intelligently controlled by the control panel 8. After the pressure reaches the set value, the exhaust valve connected to the heat release pipe 5 is opened. This part of the steam is collected at the required flow rate and pressure and released through the heat release pipe 5, and then transported to the steam turbine generator for power generation.

[0042] It should be understood that the above specific embodiments of the present application are only used to illustrate or explain the principles of the present application, and do not constitute a limitation to the present application. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present application should be included in the protection scope of the present application. In addition, the claims attached to the present application are intended to cover all changes and modifications that fall within the scope and boundaries of the attached claims, or the equivalent forms of such scope and boundaries.

Claims

1. An electrothermal conversion phase change heat storage device, characterized in that: include: Container module (1), A phase change medium storage area (2), the phase change medium storage area (2) being disposed inside the container module (1), the phase change medium storage area (2) being used to contain a phase change medium, the phase change medium generating steam by phase change; A heat storage material layer (6), wherein the heat storage material layer (6) is arranged between the phase change medium storage area (2) and the container module (1); A phase change medium feeding system, used for inputting phase change medium into the phase change medium storage area (2); A heating system, the heating system being used to heat the heat storage material layer (6); A heat release system, the heat release system is used to release steam generated by the phase change of the phase change medium; The phase change medium feeding system and the heat release system are in communication with the phase change medium storage area (2).

2. The heat storage device according to claim 1, characterized in that: The phase change medium storage area (2) is connected to a thermocouple and a pressure gauge.

3. The heat storage device according to claim 1, characterized in that: The heat storage material layer (6) is amorphous sand or powdery solid heat storage material.

4. The heat storage device according to claim 1, characterized in that: The heating system comprises a plurality of fin-type electric heaters (7), which are pre-buried in the heat storage material layer (6) and connected to an external power source, and are used to heat the heat storage material layer (6) to provide heat.

5. The heat storage device according to claim 4, characterized in that: The plurality of fin-type electric heaters (7) are evenly and staggeredly distributed in the heat storage material layer (6).

6. The heat storage device according to claim 1, characterized in that: The phase change medium feeding system comprises a phase change medium delivery pipe (3) and a phase change medium feeding pump (4); one end of the phase change medium delivery pipe (3) is mounted on the phase change medium storage area (2) and communicates with the internal space of the phase change medium storage area (2), and the other end extends to the outside of the container module (1); the phase change medium feeding pump (4) is mounted on the phase change medium delivery pipe (3).

7. The heat storage device according to claim 6, characterized in that: The flow rate of the phase change medium in the phase change medium delivery pipe (3) is 10 to 25 m / s. 3 / h.

8. The heat storage device according to claim 1, characterized in that: The heat release system comprises an exhaust valve and a heat release pipe (5); one end of the heat release pipe (5) is fixed to the phase change medium storage area (2) and communicated with the interior of the phase change medium storage area (2); the other end extends to the outside of the container module (1); the exhaust valve is installed on the phase change medium storage area (2) and communicated with the heat release pipe (5).

9. The heat storage device according to claim 1, characterized in that: The heat release system further comprises a gas flow meter, which is installed on the heat release pipe (5).

10. The heat storage device according to any one of claims 6 to 7, characterized in that: It also includes a control system, which includes a control panel (8), and the control panel (8) is electrically connected to the phase change medium feed pump (4) as well as a thermocouple and a pressure gauge.

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