Heat storage device suitable for sensible heat and phase change latent heat energy storage system and operation method

Abstract

The invention provides a heat storage device suitable for a sensible heat and phase change latent heat energy storage system and an operation method.The heat storage device comprises a heat preservation box body, a flat plate micro heat pipe is arranged in the heat preservation box body, and the two ends of the flat plate micro heat pipe are provided with an evaporation section side heat exchange water tank and a condensation section side heat exchange water tank correspondingly; the evaporation section side heat exchange water tank and the condensation section side heat exchange water tank are connected through a flow channel, a middle heat exchange water tank is arranged outside the flow channel, flat plate straight fins are arranged outside the flat plate micro heat pipes, and phase change materials are arranged in the heat preservation box body. According to the heat storage device, the flat plate micro heat pipe serves as a core heat transfer element, the whole heat storage device is formed by combining the heat conduction silica gel, the heat exchange water tank, the flat plate straight fins and the phase change materials, the heat absorption rate of the heat storage device can be effectively improved, the heat conductivity and the circulation efficiency are improved, the comprehensive performance of an energy storage system is improved, and better economic benefits are achieved.

Description

Technical Field

[0001] The invention belongs to the technical fields of solar energy, energy storage, and heat pump, and particularly relates to a heat storage device and an operation method applicable to sensible heat and latent heat of phase change energy storage systems. Background Art

[0002] Heat storage energy storage is an energy storage technology, the principle of which is to store thermal energy in the forms of sensible heat, latent heat, and thermochemistry, and release it in the form of thermal energy or other energy when needed. It has great potential in improving cycle efficiency, energy utilization efficiency, and energy conservation, and has great application value. The invention can be combined with solar energy utilization technology, and the water in the water tank is heated by sunlight, so as to store solar energy through this heat storage device and release it for utilization when needed, achieving the purpose of storing clean and sustainable energy. With the continuous growth of energy demand and the increasing emphasis on environmental protection, heat storage energy storage technology, as an effective way of energy storage and utilization, will be more widely applied and developed in the future. The future development trends mainly include developing high-performance heat storage materials, improving energy storage density and efficiency; researching new heat storage energy storage systems to achieve better integration with renewable energy and other energy systems; optimizing the cost-effectiveness of heat storage energy storage technology and reducing investment and operation costs, etc. Summary of the Invention

[0003] To overcome the deficiencies of the above-mentioned prior art, the invention provides a heat storage device and an operation method applicable to sensible heat and latent heat of phase change energy storage systems. The heat storage device takes flat micro heat pipes as the core heat transfer elements, and combines thermal conductive silica gel, a heat exchange water tank, flat straight fins, and phase change materials to form the entire heat storage device. This device can effectively improve the heat absorption rate of the heat storage device, increase the heat conduction rate and cycle efficiency, improve the comprehensive performance of the energy storage system, and has better economic benefits.

[0004] To achieve the above technical features, the object of the invention is realized as follows: A heat storage device applicable to sensible heat and latent heat of phase change energy storage systems, the heat storage device includes a heat preservation box body, a flat micro heat pipe is arranged inside the heat preservation box body, evaporation section side heat exchange water tanks and condensation section side heat exchange water tanks are respectively arranged at both ends of the flat micro heat pipe, the evaporation section side heat exchange water tanks and the condensation section side heat exchange water tanks are connected by a flow channel, a middle heat exchange water tank is arranged outside the flow channel, flat straight fins are arranged outside the flat micro heat pipe, and phase change materials are arranged inside the heat preservation box body.

[0005] Preferably, the flat micro heat pipe structure is composed of three parts: an evaporation section, an adiabatic section, and a condensation section; a working medium with a filling ratio of 20% is introduced into the microchannels of the flat micro heat pipe.

[0006] Preferably, flat straight fins are attached to both sides of the adiabatic section of the flat micro heat pipe; one side of the evaporation section of the flat micro heat pipe is attached to the heat exchange water tank on the side of the evaporation section, and one side of the condensation section of the flat micro heat pipe is attached to the heat exchange water tank on the side of the condensation section. The heat storage device is placed in a heat preservation box and filled with a phase change material.

[0007] Preferably, the flat micro heat pipe is a heat pipe with axial heat transfer and can achieve long-distance heat transfer. It is processed into a multi-channel aluminum flat tube by hot extrusion technology, and the inside of the channel has a micro fin structure to enhance the heat transfer effect of the heat pipe.

[0008] Preferably, a liquid working medium is introduced into the flat micro heat pipe as the working fluid.

[0009] Preferably, the evaporation section and the condensation section of the flat micro heat pipe are respectively attached to the heat exchange water tank on the side of the evaporation section and the heat exchange water tank on the side of the condensation section through heat-conducting silica gel. The heat-conducting silica gel is used to reduce the thermal resistance of the contact surface to enhance the heat exchange performance.

[0010] Preferably, both the heat exchange water tank on the side of the evaporation section and the heat exchange water tank on the side of the condensation section are made of aluminum materials.

[0011] On the other hand, the present invention provides an operation method for a heat storage device applicable to a sensible heat and latent heat of phase change energy storage system: Hot water flows into the heat exchange water tank on the side of the evaporation section and the middle heat exchange water tank from the bottom flow channel inlet through a water pump. The heat exchange water tank on the side of the evaporation section provides a constant heat source for the evaporation section of the flat micro heat pipe. The working medium inside the evaporation section absorbs heat and evaporates, and flows towards the adiabatic section under the action of pressure difference and buoyancy. The outside of the adiabatic section is a rectangular box filled with a phase change material. The heat released by the steam in the adiabatic section is absorbed by the phase change material through the conduction of the flat straight fins. At the same time, the heat of the hot water in the middle heat exchange water tank is absorbed by the phase change material through the conduction of the flat straight fins. The phase change material undergoes a phase change when reaching the critical temperature, thereby completing the heat storage through the phase change process and realizing heat storage. Cold water flows into the heat exchange water tank on the side of the condensation section from the top flow channel inlet through a water pump. The heat exchange water tank on the side of the condensation section provides a constant cold source for the condensation section of the flat micro heat pipe. The heat stored in the phase change material is released, transferred to the flat micro heat pipe through the flat straight fins. The working medium in the heat pipe absorbs heat and evaporates, and flows towards the condensation section under the action of pressure difference and buoyancy. It releases heat and condenses on the wall surface of the condensation section. The heat released by the gaseous working medium in the condensation section is absorbed by the cold water, thereby taking away the stored heat through the water and realizing heat release.

[0012] The present invention has the following beneficial effects: 1. In the heat storage device of the present invention, a flat micro heat pipe is used as the core heat exchange element, and the element adopts a form of combining a micro heat pipe with flat straight fins. The flat micro heat pipe has a high heat transfer coefficient and can quickly and evenly transfer the heat (cold) in the heat exchange fluid to the PCM through the side and the middle water tank of the flat micro heat pipe, realizing the rapid transfer and storage of energy.

[0013] 2. In the heat storage device of the present invention, the flat micro heat pipes are symmetrically arranged at the four corners of the heat storage shell, effectively improving the problem of slow melting of the PCM at the four corners of the heat storage shell. In addition, this structure is different from the heat storage shell established in the width direction of the flat micro heat pipe, which can increase the volume of the heat storage shell and fill more PCM under the same number of flat micro heat pipes, so as to improve its heat storage performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described below in conjunction with the drawings and embodiments.

[0015] Figure 1 It is the overall framework diagram of the heat storage device.

[0016] Figure 2 It is the front view of the heat storage device.

[0017] Figure 3 It is the top view of the heat storage device.

[0018] Figure 4 It is the cross-sectional view of the flat micro heat pipe.

[0019] In the figure: 1 heat preservation box body, 2 side heat exchange water tank of the condensation section, 3 flow channel, 4 side heat exchange water tank of the evaporation section, 5 middle heat exchange water tank, 6 phase change material, 7 flat straight fins, 8 flat micro heat pipe. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The embodiments of the present invention will be further described below in conjunction with the drawings.

[0021] Embodiment 1: Refer to Figures 1-4, a heat storage device applicable to sensible heat and phase change latent heat energy storage systems. The heat storage device includes a heat preservation box body 1. Inside the heat preservation box body 1, there is a flat micro heat pipe 8. At both ends of the flat micro heat pipe 8, there are respectively an evaporation section side heat exchange water tank 4 and a condensation section side heat exchange water tank 2. The evaporation section side heat exchange water tank 4 and the condensation section side heat exchange water tank 2 are connected by a flow channel 3. Outside the flow channel 3, there is a middle heat exchange water tank 5. Outside the flat micro heat pipe 8, there are flat straight fins 7. Inside the heat preservation box body 1, there is a phase change material 6. This heat storage device uses the flat micro heat pipe as the core heat transfer element and combines thermal conductive silicone, heat exchange water tanks, flat straight fins, and phase change materials to form the entire heat storage device. This device can effectively improve the heat absorption rate of the heat storage device, improve the thermal conductivity and circulation efficiency, improve the comprehensive performance of the energy storage system, and has better economic benefits.

[0022] Further, the structure of the flat micro heat pipe 8 consists of three parts: an evaporation section, an adiabatic section, and a condensation section; a working medium with a filling ratio of 20% is introduced into the microchannels of the flat micro heat pipe 8. The heat exchange efficiency is improved through the above-mentioned flat micro heat pipe 8.

[0023] Further, flat straight fins 7 are attached to both sides of the adiabatic section of the flat micro heat pipe 8; on one side of the evaporation section of the flat micro heat pipe 8, it is attached to the evaporation section side heat exchange water tank 4, and on one side of the condensation section of the flat micro heat pipe 8, it is attached to the condensation section side heat exchange water tank 2. The heat storage device is placed in the heat preservation box body 1 and filled with the phase change material 6. The heat exchange area is increased through the flat straight fins 7, thereby improving the heat exchange efficiency.

[0024] Further, the flat micro heat pipe 8 is a heat pipe with axial heat transfer and can achieve long-distance heat transfer. It is processed into a multi-channel aluminum flat tube through a hot extrusion technique, and the inside of the channel has a micro fin structure to enhance the heat transfer effect of the heat pipe.

[0025] Further, a liquid working medium is introduced into the flat micro heat pipe 8 as the working fluid.

[0026] Further, the evaporation section and the condensation section of the flat micro heat pipe 8 are respectively attached to the evaporation section side heat exchange water tank 4 and the condensation section side heat exchange water tank 2 through thermal conductive silicone. The thermal conductive silicone is used to reduce the thermal resistance of the contact surface to enhance the heat exchange performance.

[0027] Further, both the evaporation section side heat exchange water tank 4 and the condensation section side heat exchange water tank 2 are respectively made of aluminum materials.

[0028] Embodiment 2: An operating method of a heat storage device applicable to sensible heat and phase change latent heat energy storage systems: Hot water flows into the side heat exchange water tank 4 and the middle heat exchange water tank 5 of the evaporation section from the inlet of the bottom flow channel 3 through a water pump. The side heat exchange water tank 5 of the evaporation section provides a constant heat source for the evaporation section of the flat micro heat pipe 8. The working fluid inside the evaporation section absorbs heat and evaporates, and flows towards the adiabatic section under the action of pressure difference and buoyancy. The outside of the adiabatic section is a rectangular box filled with phase change material 6. The heat released by the steam in the adiabatic section is conducted through the flat straight fins 7 and absorbed by the phase change material 6. At the same time, the heat of the hot water in the middle heat exchange water tank 5 is conducted through the flat straight fins 7 to the phase change material 6 for absorption. When the phase change material reaches the critical temperature, a phase change occurs, thereby completing the heat storage through the phase change process and realizing heat storage; Cold water flows into the side heat exchange water tank 2 of the condensation section from the inlet of the top flow channel 3 through a water pump. The side heat exchange water tank 2 of the condensation section provides a constant cold source for the condensation section of the flat micro heat pipe 8. The heat stored in the phase change material 6 is released, transferred to the flat micro heat pipe 8 through the flat straight fins 7. The working fluid in the heat pipe absorbs heat and evaporates, and flows towards the condensation section under the action of pressure difference and buoyancy, and releases heat and condenses on the wall of the condensation section. The heat released by the gaseous working fluid in the condensation section is absorbed by the cold water, thereby taking away the stored heat through the water and realizing heat release.

[0029] Example 3: Operation method of the heat storage device of the sensible heat and latent heat of phase change energy storage system: Method for the heat storage device to store heat: During the heat storage stage, when the temperature of the water in the constant temperature water bath is stable at 75 °C, the water in the water bath passes through a water pump and is transported to the five-way joint through a hose connected to the circulation outlet, and flows into the heat exchange water tank of the evaporation section of the flat micro heat pipe through shunting. At this time, the evaporation section of the flat micro heat pipe is heated. When the temperature of the evaporation section of the flat micro heat pipe reaches the phase change temperature of the working fluid inside the flat micro heat pipe, the internal working fluid absorbs heat and evaporates. The steam brings the heat to the adiabatic section of the flat micro heat pipe, and transfers the heat to the pipe wall of the flat micro heat pipe and the fins on its surface in the adiabatic section, and is absorbed by the phase change material (PCM) between the adiabatic section and the fins of the flat micro heat pipe. The water converging from the side water tank of the evaporation section flows into the flow channel of the middle water tank of the heat storage box through a water pipe, and transfers the heat to the surrounding PCM through the box and the fins on the surface of the box. When the temperature continues to rise and reaches the phase change temperature of the PCM, the solid PCM gradually transforms into a liquid state, storing the absorbed sensible heat and latent heat of phase change in the liquid PCM, and completing the heat storage process.

[0030] Method for the heat storage device to release heat: During the heat release stage, when the temperature of the water in the constant temperature water bath is stable at 15 °C, the water flows through the water pump and is pumped into the heat exchange water tank attached to the condensation section of the flat micro heat pipe. The fluid after heat exchange converges into the middle water tank and exchanges heat with the surrounding liquid PCM, and then flows back to the constant temperature water bath through a hose. The heat stored in the liquid PCM is taken away through the heat exchange of the flat micro heat pipe and the middle water tank, thereby completing the heat release process.

Claims

1. A heat storage device applicable to sensible heat and phase change latent heat energy storage systems, characterized in that, The heat storage device includes a heat insulation box body (1). Inside the heat insulation box body (1), there is a flat micro heat pipe (8). At both ends of the flat micro heat pipe (8), there are respectively an evaporation section side heat exchange water tank (4) and a condensation section side heat exchange water tank (2). The evaporation section side heat exchange water tank (4) and the condensation section side heat exchange water tank (2) are connected by a flow channel (3). Outside the flow channel (3), there is a middle heat exchange water tank (5). Outside the flat micro heat pipe (8), there are flat straight fins (7). Inside the heat insulation box body (1), there is a phase change material (6).

2. The heat storage device applicable to sensible heat and latent heat of phase change energy storage system according to claim 1, wherein: The structure of the flat micro heat pipe (8) consists of three parts: an evaporation section, an adiabatic section, and a condensation section. In the microchannels of the flat micro heat pipe (8), a working fluid with a filling ratio of 20% is introduced.

3. The heat storage device applicable to sensible heat and phase change latent heat energy storage systems according to claim 1, characterized in that: On both sides of the adiabatic section of the flat micro heat pipe (8), the flat straight fins (7) are attached. On one side of the evaporation section of the flat micro heat pipe (8), the evaporation section side heat exchange water tank (4) is attached, and on one side of the condensation section of the flat micro heat pipe (8), the condensation section side heat exchange water tank (2) is attached. The heat storage device is placed in the heat insulation box body (1) and filled with the phase change material (6).

4. The heat storage device applicable to sensible heat and phase change latent heat energy storage system according to claim 1, wherein: The flat micro heat pipe (8) is a heat pipe for axial heat transfer and can achieve long-distance heat transfer. It is processed into a multi-channel aluminum flat tube through a hot extrusion technique, and there is a micro fin structure inside the channels to enhance the heat transfer effect of the heat pipe.

5. The heat storage device applicable to sensible heat and latent heat of phase change energy storage system according to claim 4, characterized in that: A liquid working fluid is introduced into the flat micro heat pipe (8) as the working fluid.

6. The heat storage device applicable to sensible heat and latent heat of phase change energy storage system according to claim 4, characterized in that: The evaporation section and the condensation section of the flat micro heat pipe (8) are respectively attached to the evaporation section side heat exchange water tank (4) and the condensation section side heat exchange water tank (2) through thermal conductive silica gel. The thermal conductive silica gel is used to reduce the thermal resistance of the contact surface to enhance the heat exchange performance.

7. The heat storage device applicable to sensible heat and latent heat of phase change energy storage systems according to claim 6, characterized in that: Both the evaporation section side heat exchange water tank (4) and the condensation section side heat exchange water tank (2) are made of aluminum materials respectively.

8. The operation method of a heat storage device according to any one of claims 1-7, which is applicable to a sensible heat and phase change latent heat energy storage system, characterized in that: Hot water flows into the evaporation section side heat exchange water tank (4) and the middle heat exchange water tank (5) from the inlet of the bottom flow channel (3) through a water pump. The evaporation section side heat exchange water tank (5) provides a constant heat source for the evaporation section of the flat micro heat pipe (8). The working fluid inside the evaporation section absorbs heat and evaporates, and under the action of pressure difference and buoyancy force, it flows towards the adiabatic section. The outside of the adiabatic section is a rectangular box filled with the phase change material (6). The heat released by the steam in the adiabatic section is conducted through the flat straight fins (7) and absorbed by the phase change material (6). At the same time, the heat of the hot water in the middle heat exchange water tank (5) is conducted through the flat straight fins (7) and absorbed by the phase change material (6). When the phase change material reaches the critical temperature, a phase change occurs, and thus the heat storage is completed through the phase change process to achieve heat storage; Cold water flows into the side heat exchange water tank (2) of the condensation section from the inlet of the top flow channel (3) through a water pump. The side heat exchange water tank (2) of the condensation section provides a constant cold source for the condensation section of the flat micro heat pipe (8). The heat stored in the phase change material (6) is released and transferred to the flat micro heat pipe (8) through the flat straight fins (7). The working fluid in the heat pipe absorbs heat and evaporates, flows towards the condensation section under the action of pressure difference and buoyancy force, releases heat and condenses on the wall surface of the condensation section. The heat released by the gaseous working fluid in the condensation section is absorbed by the cold water, so that the stored heat is taken away by the water, realizing heat release.

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