Small distributed solar photo-thermal power generation device based on liquid thermal battery

Abstract

The invention discloses a small distributed solar photo-thermal power generation device based on a liquid thermal battery. The small distributed solar photo-thermal power generation device comprises a solar absorber module, a liquid thermal battery power generation module and a heat dissipation module 300 which are distributed in a layered mode from top to bottom. Wherein the working temperature of the hot electrode plate 201 in the liquid thermal battery power generation module is higher than that of the cold electrode plate 203. The small distributed solar photo-thermal power generation device has the beneficial effect that the small distributed solar photo-thermal power generation device is composed of the solar absorption module, the liquid thermal battery power generation module and the heat dissipation module. And a liquid thermal battery is used as a power generation module, so that the cost-performance index is lower than that of a solid-state thermoelectric conversion technology. The cost-performance index of the liquid thermal battery is estimated to be several dollars per watt, and the relative Carnot efficiency is 11.1%. A heat-sensitive crystallization and dissolution process is used in the thermal battery power generation module to induce the persistent concentration gradient of redox ions, so that the seebeck coefficient is improved, and meanwhile, the thermal conductivity is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of solar thermal power generation, in particular to a small-scale distributed solar thermal power generation device based on liquid thermal batteries. Background Art

[0002] With the continuous growth of global energy demand and the increasingly severe environmental problems, the development and utilization of solar energy as a clean and renewable energy has received widespread attention. Solar power generation technology mainly covers two major areas: photovoltaic power generation and solar thermal power generation. Among them, solar thermal power generation technology heats the working fluid through the thermal effect of solar radiation, and then drives the heat engine (such as a steam turbine) to generate power. Its advantage is that it can make full use of the entire solar spectrum band, providing an effective supplement to photovoltaic power generation. In addition, with the integration of heat storage technology, solar thermal power generation has demonstrated all-weather, continuous and stable power generation capabilities, and is not affected by solar radiation fluctuations. Compared with photovoltaic power generation, solar thermal power generation technology has higher photoelectric conversion efficiency, thermal stability and the potential for easy scale. However, it also faces a series of challenges in practical applications, such as high economic cost, complex system structure, and relatively limited output power, which limit the widespread promotion of its commercial application. In particular, the application of concentrating modules can enhance the energy flux density of the heat absorption surface, but it also brings about an increase in system complexity, an increase in cost, and a decrease in overall photoelectric conversion efficiency. In addition, traditional solar thermal power generation systems rely on the thermal cycle of large turbine machinery to generate electricity, which not only involves high initial investment, but also noise, wear and tear during operation, and high maintenance costs. In recent years, solid-state micro-heat engines, such as thermoelectric generators based on the semiconductor Seebeck effect, thermionic generators based on the metal thermionic emission effect, and thermophotovoltaic devices based on the photovoltaic effect, have shown significant advantages such as simple operation and maintenance, high stability, strong scalability, and low cost because they do not require mechanical moving parts. However, the widespread application of these technologies is still limited by challenges such as high material costs and complex micro-nano process technologies, and their cost-performance indicators have not yet reached the ideal level for large-scale commercial applications. Summary of the invention

[0003] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0004] In view of the above problems or problems existing in the prior art, the present invention is proposed.

[0005] Therefore, the purpose of the present invention is to provide a small-scale distributed solar thermal power generation device based on liquid thermal batteries, which can provide a small-scale distributed solar thermal power generation device based on liquid thermal batteries without the need for a concentrating module, low cost, and high photoelectric conversion efficiency, aiming to significantly improve the energy efficiency conversion rate and economic feasibility of solar thermal power generation technology. Compared with thermophotovoltaic devices, the present invention can realize distributed solar thermal power generation without the need for a concentrating module, and is suitable for use as a small power source in areas without or short of electricity; in addition, while reducing costs and system complexity, it achieves a higher overall photoelectric conversion efficiency. .

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a small-scale distributed solar thermal power generation device based on liquid thermal batteries, which includes a solar absorber module, a liquid thermal battery power generation module and a heat dissipation module 300 distributed in layers from top to bottom;

[0007] Among them, the working temperature of the hot electrode plate 201 in the liquid thermal battery power generation module is higher than the working temperature of the cold electrode plate 203.

[0008] As a preferred solution of the small-scale decentralized solar thermal power generation device based on liquid thermal battery of the present invention, wherein: the solar absorber module comprises a solar absorber 101, which is used to directly absorb solar energy and convert it into thermal energy, and to increase the temperature of the solar absorber and the hot electrode plate;

[0009] The energy absorbed by the solar absorber is Q ab Satisfies the following formula:

[0010] Q abs =G solar *η op *α abs *A abs

[0011] Among them, G solar =1000Wm -2 and η op are the solar spectrum irradiance and the photothermal conversion efficiency of the absorber, α abs , A abs are the absorptivity and surface area of ​​the solar absorber, respectively.

[0012] As a preferred solution of the small-scale distributed solar thermal power generation device based on liquid thermal battery of the present invention, wherein: the liquid thermal battery power generation module includes a hot electrode plate 201, an electrolyte 202 between the electrode plates, a cold electrode plate 203, and an adjustable load 204 connected between the two electrode plates by a wire;

[0013] The main components of the electrolyte are 0.4M K3Fe(CN)6 / K4Fe(CN)6 aqueous solution and a certain amount of inducing ions guanidine ions Gdm+.

[0014] As a preferred solution of the small-scale distributed solar thermal power generation device based on liquid thermal battery of the present invention, the hot electrode plate 201 and the solar absorber 101 are closely attached through the insulating thermal conductive silicone layer, and the cold electrode plate 203 and the heat dissipation module 300 are closely attached through the insulating thermal conductive silicone layer;

[0015] Among them, there is the following energy balance relationship between the hot electrode plate 201 and the environment:

[0016] Q abs =Q rad +Q H +K ce *(T H -TE)*A abs +K ce *(T H -TE)*(A LTC -Aabc)

[0017] Among them, Q rad is the radiation heat flow rate between the solar absorber and the environment, Q H is the heat flow rate from the absorber into the liquid thermal battery, K ce is the thermal convection coefficient, T H is the temperature of the hot electrode, T E is the ambient temperature, A LTC is the area of ​​the liquid thermal battery.

[0018] As a preferred solution of the small-scale distributed solar thermal power generation device based on liquid thermal battery of the present invention, wherein: the heat dissipation module 300 adopts forced convection or natural convection to discharge the waste heat that cannot be converted into electrical energy to the outside;

[0019] The following heat balance equation exists at the cold electrode plate:

[0020] Q C =K con *(T C -TE)*A LTC

[0021] Among them, Q C is the heat flux rate released by the cold electrode, K con is the average heat transfer coefficient between the heat dissipation module and the environment, T C is the cold electrode temperature, T E is the ambient temperature.

[0022] As a preferred solution of the small-scale distributed solar thermal power generation device based on liquid thermal battery of the present invention, the output power P of the power generation device satisfies the following formula:

[0023] P=Q H -Q C =A LTC *[S e *(T H -T C )*j LTC -j LTC *R cell ]

[0024] Among them, A LTC is the area of ​​the liquid thermal battery, S e is the Seebeck coefficient, j LTC is the current density of the liquid thermal battery, R cell is the resistance value of the liquid thermal battery.

[0025] As a preferred solution of the small-scale distributed solar thermal power generation device based on liquid thermal battery of the present invention, the overall energy conversion efficiency η of the power generation device satisfies the following formula:

[0026]

[0027] Among them, P is the output power, G is the solar spectrum irradiance, A is abs is the surface area of ​​the solar absorber.

[0028] As a preferred solution of the small-scale distributed solar thermal power generation device based on liquid thermal battery of the present invention, the output voltage V of the power generation device satisfies the following formula:

[0029] V=S e *(T H -T C )

[0030] Among them, S e is the Seebeck coefficient, T H is the temperature of the hot electrode, T C is the cold electrode temperature.

[0031] As a preferred solution of the small-scale distributed solar thermal power generation device based on liquid thermal battery of the present invention, wherein: the output current of the liquid thermal battery is adjusted to an optimal value by adjusting the adjustable load 204, so that the efficiency of the power generation device is maximized;

[0032] The heat flux Q received by the liquid thermal battery from the solar absorber is H and the heat flux Q released to the environment through the heat dissipation module CSatisfy the following formulas respectively:

[0033]

[0034] Q C =A LTC *[S e *T C *j LTC +κ*(T H -T C ) / L cell +0.5j LTC *R cell ]

[0035] Among them, A LTC is the area of ​​the liquid thermal battery, S e =3.73×10 -3 VK -1 is the Seebeck coefficient, j LTC is the current of the liquid thermal battery, which is controlled by adjusting the adjustable load 204, κ=0.4Wm -1 K -1 is the effective thermal conductivity, T C is the temperature of the cold electrode of the liquid thermal battery, R cell is the resistance value of the liquid thermal battery, L cell is the thickness of the liquid thermal battery.

[0036] As a preferred solution of the small-scale distributed solar thermal power generation device based on liquid thermal battery of the present invention, the performance of the power generation device can be optimized by the following parameters:

[0037] The area ratio of the solar absorber 101 to the liquid thermal battery is χ = A abs / A LTC ;

[0038] Thermal conductivity K con ;

[0039] Thermal convection coefficient K ce ;

[0040] Ambient temperature T E ;

[0041] Thickness L of liquid thermal battery cell ;

[0042] Among them, the maximum power density P of the power generation device and the corresponding efficiency η vary with χ=A abs / A LTC , K con and L cell increases with the increase of K ce and T E decreases with the increase of .

[0043] Beneficial effects of the invention: The present invention proposes and designs a small-scale decentralized solar thermal power generation device consisting of a solar absorption module, a liquid thermal battery power generation module and a heat dissipation module for the first time. The device has a simple structure and does not require a concentrating module, which reduces the overall cost of power generation and improves the overall photoelectric conversion efficiency. It uses liquid thermal batteries as power generation modules and has lower cost-performance indicators than solid-state thermoelectric conversion technology. The cost-performance indicator of liquid thermal batteries is estimated to be several dollars per watt, and the relative Carnot efficiency is 11.1%. Thermosensitive crystallization and dissolution processes are used in the thermal battery power generation module to induce a persistent concentration gradient of redox ions, which increases the Seebeck coefficient while reducing thermal conductivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0045] Figure 1 This is a schematic diagram of the overall structure of a small-scale distributed solar thermal power generation device based on liquid thermal batteries.

[0046] Figure 2 Schematic diagram of the relationship between power density, efficiency and current density of a small-scale distributed solar thermal power generation device based on liquid thermal batteries.

[0047] Figure 3 Schematic diagram of the changing relationship between maximum power density, efficiency and area ratio of a small-scale distributed solar thermal power generation device based on liquid thermal batteries.

[0048] Figure 4 Schematic diagram of the changing relationship between the maximum power density, efficiency and thermal conductivity of a small-scale distributed solar thermal power generation device based on liquid thermal batteries.

[0049] Figure 5 Schematic diagram of the changing relationship between the maximum power density, efficiency and thermal convection coefficient of a small-scale distributed solar thermal power generation device based on liquid thermal batteries.

[0050] Figure 6 Schematic diagram of the relationship between the maximum power density, efficiency and ambient temperature of a small-scale distributed solar thermal power generation device based on liquid thermal batteries.

[0051] Figure 7 The maximum power density, efficiency and performance of small-scale distributed solar thermal power generation devices based on liquid thermal batteries are LTCSchematic diagram of the relationship between the changes in size. DETAILED DESCRIPTION

[0052] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0053] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0054] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0055] Example 1

[0056] Reference Figure 1 , which is the first embodiment of the present invention, provides a small-scale distributed solar thermal power generation device based on liquid thermal battery, which includes a solar absorber module, a liquid thermal battery power generation module and a heat dissipation module. The solar absorber module includes a solar absorber 101, which is used to directly absorb solar energy and convert it into thermal energy; the liquid thermal battery power generation module includes a hot electrode plate 201, an electrolyte 202, a cold electrode plate 203 and an adjustable load 204, which are used to convert thermal energy into electrical energy; and the heat dissipation module 300 is used to discharge the waste heat. After the solar absorber 101 absorbs solar energy, it is closely attached to the hot electrode plate 201 through the insulating thermal conductive silicone layer to increase the temperature of the hot electrode plate 201. When there is a temperature difference between the hot electrode plate 201 and the cold electrode plate 203, the redox ions in the electrolyte 202 form a concentration gradient between the two electrodes, thereby generating a potential difference to drive the adjustable load 204 in the external circuit to achieve power generation. The heat dissipation module 300 is tightly attached to the cold electrode plate 203 through an insulating thermally conductive silicone layer, and discharges the waste heat that cannot be converted into electrical energy to the outside, maintaining the temperature difference of the system and ensuring continuous power generation.

[0057] Specifically, the solar absorber module, the liquid thermal battery power generation module and the heat dissipation module 300 are distributed in layers from top to bottom;

[0058] Among them, the working temperature of the hot electrode plate 201 in the liquid thermal battery power generation module is higher than the working temperature of the cold electrode plate 203.

[0059] Preferably, the solar absorber module receives the full spectrum of sunlight and converts it into thermal energy, and the power generation module is a liquid thermal battery, which converts the thermal energy from the solar absorber 101 into electrical energy;

[0060] The hot electrode plate 201 is closely attached to the solar absorber 101 through an insulating thermally conductive silicone layer to absorb heat energy from the solar absorber 101; the cold electrode plate 203 is closely attached to the heat dissipation module 300 through an insulating thermally conductive silicone layer. The insulating thermally conductive silicone can achieve good heat transfer and shield charge exchange.

[0061] Furthermore, the liquid thermal battery power generation module includes a hot electrode plate 201, an electrolyte 202 between the electrode plates, a cold electrode plate 203, and an adjustable load 204 connected between the two electrode plates by a wire;

[0062] The main components of the electrolyte are 0.4M K3Fe(CN)6 / K4Fe(CN)6 aqueous solution and a certain amount of inducing ions guanidine ions Gdm+.

[0063] Preferably, solar energy is absorbed by the solar absorber 101, increasing the temperature of the solar absorber 101. The heat energy from the solar absorber 101 increases the temperature of the hot electrode plate 201, and after stabilization, the temperature of the hot electrode plate 201 is equal to the temperature of the solar absorber 101. When there is a temperature difference between the hot electrode plate 201 and the cold electrode plate 203, the hot electrode plate 201 undergoes an oxidation reaction. Oxidized to On the contrary, the cold electrode plate 203 undergoes a reduction reaction, Restore to Since the destruction of the reversible reaction balance between the redox pairs leads to the opposite reaction at the same time, a potential difference is generated on each electrode, driving the adjustable load connected in series with the external circuit to realize the conversion of thermal energy into output electrical energy.

[0064] Preferably, the heat dissipation module 300 uses forced convection (with external cooling fluid) or natural convection to discharge the waste heat that cannot be converted into electrical energy to the outside, thereby achieving energy balance.

[0065] It should be noted that as an energy conversion device, the most important technical parameters of the liquid thermal battery solar energy utilization device are its power output P and energy conversion efficiency η. The performance characteristics of the liquid thermal battery solar energy utilization device are calculated in accordance with the first law of thermodynamics and Newton's law of heat transfer.

[0066] In summary, the present invention proposes and designs a small-scale distributed solar thermal power generation device composed of a solar absorption module, a liquid thermal battery power generation module and a heat dissipation module for the first time. The device has a simple structure and does not require a concentrating module, which reduces the overall cost of power generation and improves the overall photoelectric conversion efficiency. It uses liquid thermal batteries as power generation modules and has lower cost-performance indicators than solid-state thermoelectric conversion technology.

[0067] Example 2

[0068] Reference Figures 1 to 7 , which is the second embodiment of the present invention, provides a small-scale decentralized solar thermal power generation device based on liquid thermal batteries, which includes an introduction to the design method of two key indicators of the liquid thermal battery solar energy utilization device. The simulation calculation and verification are both implemented by Mathematica software, and the graphics are drawn by Origin software.

[0069] Specifically, the solar absorber module includes a solar absorber 101, which is used to directly absorb solar energy and convert it into thermal energy, and to increase the temperature of the solar absorber and the thermocouple plate;

[0070] The energy absorbed by the solar absorber is Q ab Satisfies the following formula:

[0071] Q abs =G solar *η op *α abs *A abs

[0072] Among them, G solar =1000Wm -2 and η op are the solar spectrum irradiance and the photothermal conversion efficiency of the absorber, α abs , A abs are the absorptivity and surface area of ​​the solar absorber, respectively.

[0073] Preferably, the solar radiation energy flow Q S The incident energy Q is incident on the solar absorber 101, and the energy Q absorbed by the solar absorber 101 ab , the temperature of the thermocouple plates of the absorber and the power generation module is in thermal equilibrium, and the temperature is T H .

[0074] Furthermore, the hot electrode plate 201 and the solar absorber 101 are closely attached via an insulating thermally conductive silicone layer, and the cold electrode plate 203 and the heat dissipation module 300 are closely attached via an insulating thermally conductive silicone layer;

[0075] The temperature of the solar absorber 101 and the hot electrode plate 201 of the power generation module are in thermal equilibrium, and the temperature is. Considering Newton's heat transfer law T H , there is the following energy balance relationship,

[0076] Among them, there is the following energy balance relationship between the hot electrode plate 201 and the environment:

[0077] Q abs =Q rad +Q H +K ce *(T H -T E )*A abs +K ce *(T H -T E )*(A LTC -A abs )

[0078] Among them, Q rad is the radiation heat flow rate between the solar absorber and the environment, Q H is the heat flow rate from the absorber into the liquid thermal battery, K ce is the thermal convection coefficient, T H is the temperature of the hot electrode, T E is the ambient temperature, A LTC is the area of ​​the liquid thermal battery.

[0079] Preferably, in addition to absorbing and reflecting light, the absorber also dissipates heat to the environment through thermal radiation due to its own high temperature. The radiation heat flow rate Q between the absorber and the environment rad satisfies the Stefan-Boltzmann law.

[0080]

[0081] Where, σ = 5.67 × 10 -8 Wm -2 K -4 is the Stefan-Boltzmann constant. In thermal equilibrium, the absorptivity and emissivity of the light absorber satisfy Kirchhoff's law, that is, ε abs =α abs ,

[0082] Furthermore, the heat dissipation module 300 uses forced convection or natural convection to discharge the waste heat that cannot be converted into electrical energy to the outside;

[0083] The following heat balance equation exists at the cold electrode plate:

[0084] Q C =K con *(T C-T E )*A LTC

[0085] Among them, Q C is the heat flux rate released by the cold electrode, K con is the average heat transfer coefficient between the heat dissipation module and the environment, T C is the cold electrode temperature, T E is the ambient temperature.

[0086] Furthermore, the output power P of the power generation device satisfies the following formula:

[0087] P=Q H -Q C =A LTC *[S e *(T H -T C )*j LTC -j LTC *R cell ]

[0088] Among them, A LTC is the area of ​​the liquid thermal battery, S e is the Seebeck coefficient, j LTC is the current density of the liquid thermal battery, R cell is the resistance value of the liquid thermal battery.

[0089] Furthermore, the overall energy conversion efficiency η of the power generation device satisfies the following formula:

[0090]

[0091] Among them, P is the output power, G is the solar spectrum irradiance, A is abs is the surface area of ​​the solar absorber.

[0092] Furthermore, the output voltage V of the power generation device satisfies the following formula:

[0093] V=S e *(T H -T C )

[0094] Among them, S e is the Seebeck coefficient, T H is the temperature of the hot electrode, T C is the cold electrode temperature.

[0095] Furthermore, the output current of the liquid thermal battery is adjusted to an optimal value by adjusting the adjustable load 204, thereby maximizing the efficiency of the power generation device;

[0096] The heat flux Q received by the liquid thermal battery from the solar absorber is H and the heat flux Q released to the environment through the heat dissipation module C Satisfy the following formulas respectively:

[0097]

[0098] Q C =A LTC *[S e *T C *j LTC +κ*(T H -T C ) / L cell +0.5j LTC *R cell ]

[0099] Among them, A LTC is the area of ​​the liquid thermal battery, S e =3.73×10 -3 VK -1 is the Seebeck coefficient, j LTC is the current of the liquid thermal battery, which is controlled by adjusting the adjustable load 204, κ=0.4Wm -1 K -1 is the effective thermal conductivity, T C is the temperature of the cold electrode of the liquid thermal battery, R cell is the resistance value of the liquid thermal battery, L cell is the thickness of the liquid thermal battery.

[0100] Furthermore, the performance of the power generation device can be optimized by the following parameters:

[0101] The area ratio of the solar absorber 101 to the liquid thermal battery is χ = A abs / A LTC ;

[0102] Thermal conductivity K con ;

[0103] Thermal convection coefficient K ce ;

[0104] Ambient temperature T E ;

[0105] Thickness L of liquid thermal battery cell ;

[0106] Among them, the maximum power density P of the power generation device and the corresponding efficiency η vary with χ=A abs / A LTC , K con and L cell increases with the increase of Kce and T E decreases with the increase of .

[0107] Preferably, when the absorption degree of the absorption module is constant, the output current of the LTC can be adjusted by the adjustable load to maximize the efficiency of the power generation device. After numerical calculation, Figure 2 The relationship between the device's power density P, efficiency η and current density is given. As can be seen from the figure, with the change of current density, the device's power density and efficiency have maximum values;

[0108] exist Figure 2 Based on the change of the solar absorber and liquid thermal battery area ratio χ = A abs / A LTC , the relationship between the maximum power density P of the power generation device and the corresponding efficiency η and the area ratio X can be obtained. The maximum power density P of the power generation device and the corresponding efficiency η increase with the increase of the area ratio X;

[0109] exist Figure 2 Based on the change of thermal conductivity K con , we can get the maximum power density P of the power generation device and the corresponding efficiency η and thermal conductivity K con The relationship between the maximum power density P of the power generation device and the corresponding efficiency η varies with the thermal conductivity K con increases with the increase of

[0110] exist Figure 2 Based on the change of heat convection coefficient K ce , we can get the maximum power density of the power generation device and the corresponding efficiency and heat convection coefficient K ce The relationship between the maximum power density P of the power generation device and the corresponding efficiency varies with the heat convection coefficient K ce decreases with the increase of

[0111] exist Figure 2 Based on the change of ambient temperature T E , we can get the maximum power density P of the power generation device and the corresponding efficiency η and ambient temperature T E The relationship between the maximum power density P of the power generation device and the corresponding efficiency η increases with the increase of ambient temperature T E and decrease;

[0112] exist Figure 2 Based on the change of the size L of the liquid thermochemical battery LTC cell , we can get the maximum power density P of the power generation device and the corresponding efficiency η and the size L of the LTC cell The relationship between the maximum power density P of the power generation device and the corresponding efficiency η varies with the size L of the LTC cellincreases with the increase of .

[0113] It should be noted that the liquid thermal battery power generation module uses thermosensitive crystallization and dissolution processes to induce a persistent concentration gradient of redox ions, which increases the Seebeck coefficient while reducing thermal conductivity, and uses a solar absorber to reach a higher temperature and a larger heat flux density, converting solar energy into usable thermal energy. The liquid thermochemical battery is used to achieve the conversion from thermal energy to electrical energy through the temperature gradient, and an overall more ideal photoelectric conversion is achieved. The structure of the present invention is simple, and each module is independent of each other, which effectively reduces the failure rate. It can realize decentralized solar thermal power generation without the need for a concentrating module, and is suitable for use as a small power source in areas without electricity or power shortages; in addition, while reducing costs and system complexity, a higher overall photoelectric conversion efficiency is achieved.

[0114] In summary, the present invention proposes and designs a small-scale decentralized solar thermal power generation device consisting of a solar absorption module, a liquid thermal battery power generation module and a heat dissipation module for the first time. The device has a simple structure and does not require a concentrating module, which reduces the overall cost of power generation and improves the overall photoelectric conversion efficiency. It uses liquid thermal batteries as power generation modules and has lower cost-performance indicators than solid-state thermoelectric conversion technology. The cost-performance indicator of liquid thermal batteries is estimated to be a few dollars per watt, and the relative Carnot efficiency is 11.1%. Thermosensitive crystallization and dissolution processes are used in the thermal battery power generation module to induce a persistent concentration gradient of redox ions, which increases the Seebeck coefficient while reducing thermal conductivity.

[0115] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), installation arrangement, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of multiple parts or elements, the position of the element can be inverted or otherwise changed, and the nature or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present invention. The order or sequence of any process or method steps can be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure of performing the function described herein, and is not only structurally equivalent but also equivalent structure. Without departing from the scope of the present invention, other replacements, modifications, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the invention is not limited to a specific embodiment, but extends to numerous modifications still falling within the scope of the appended claims.

[0116] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0117] It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

[0118] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A small-scale distributed solar thermal power generation device based on liquid thermal batteries, characterized in that: include, A solar absorber module, a liquid thermal battery power generation module and a heat dissipation module (300) are arranged in layers from top to bottom; The operating temperature of the hot electrode plate (201) in the liquid thermal battery power generation module is higher than the operating temperature of the cold electrode plate (203).

2. The small-scale distributed solar thermal power generation device based on liquid thermal battery according to claim 1, characterized in that: The solar absorber module comprises a solar absorber (101) for directly absorbing solar energy and converting it into thermal energy, and increasing the temperature of the solar absorber and the thermocouple plate; The energy absorbed by the solar absorber is Q ab Satisfies the following formula: Q abs =G solar *or op *a abs *A abs Among them, G solar =1000Wm -2 and η op are the solar spectrum irradiance and the photothermal conversion efficiency of the absorber, α abs , A abs are the absorptivity and surface area of ​​the solar absorber, respectively.

3. The small-scale distributed solar thermal power generation device based on liquid thermal battery according to claim 2, characterized in that: The liquid thermal battery power generation module comprises a hot electrode plate (201), an electrolyte (202) between the electrode plates, a cold electrode plate (203), and an adjustable load (204) connected between the two electrode plates via a wire; The main components of the electrolyte are 0.4M K3Fe(CN)6 / K4Fe(CN)6 aqueous solution and a certain amount of inducing ions guanidine ions (Gdm+).

4. The small-scale distributed solar thermal power generation device based on liquid thermal battery according to claim 3, characterized in that: The hot electrode plate (201) and the solar absorber (101) are tightly fitted via an insulating thermally conductive silicone layer, and the cold electrode plate (203) and the heat dissipation module (300) are tightly fitted via an insulating thermally conductive silicone layer; There exists the following energy balance relationship between the hot electrode plate (201) and the environment: Q abs =Q rad +Q H +K ce *(T H -T E )*A abs +K ce *(T H -T E )*(A LTC -A abs ) Among them, Q rad is the radiation heat flow rate between the solar absorber and the environment, Q H is the heat flow rate from the absorber into the liquid thermal battery, K ce is the thermal convection coefficient, T H is the temperature of the hot electrode, T E is the ambient temperature, A LTC is the area of ​​the liquid thermal battery.

5. The small-scale distributed solar thermal power generation device based on liquid thermal battery according to claim 4, characterized in that: The heat dissipation module (300) uses forced convection or natural convection to discharge the waste heat that cannot be converted into electrical energy to the outside; The following heat balance equation exists at the cold electrode plate: Q C =K con *(T C -T E )*A LTC Among them, Q C is the heat flux rate released by the cold electrode, K con is the average heat transfer coefficient between the heat dissipation module and the environment, T C is the cold electrode temperature, T E is the ambient temperature.

6. The small-scale distributed solar thermal power generation device based on liquid thermal battery according to claim 5, characterized in that: The output electric power P of the power generation device satisfies the following formula: P=Q H -Q C =A LTC *[S e *(T H -T C )*j LTC -j LTC *R cell ] Among them, A LTC is the area of ​​the liquid thermal battery, S e is the Seebeck coefficient, j LTC is the current density of the liquid thermal battery, R cell is the resistance value of the liquid thermal battery.

7. The small-scale distributed solar thermal power generation device based on liquid thermal battery according to claim 6, characterized in that: The overall energy conversion efficiency η of the power generation device satisfies the following formula: Among them, P is the output power, G is the solar spectrum irradiance, A is abs is the surface area of ​​the solar absorber.

8. The small-scale distributed solar thermal power generation device based on liquid thermal battery according to claim 7, characterized in that: The output voltage V of the power generation device satisfies the following formula: V=S e *(T H -T C ) Among them, S e is the Seebeck coefficient, T H is the temperature of the hot electrode, T C is the cold electrode temperature.

9. The small-scale distributed solar thermal power generation device based on liquid thermal battery according to claim 8, characterized in that: By adjusting the adjustable load (204), the output current of the liquid thermal battery reaches an optimal value, thereby maximizing the efficiency of the power generation device; The heat flux Q received by the liquid thermal battery from the solar absorber is H and the heat flux Q released to the environment through the heat dissipation module C Satisfy the following formulas respectively: Q C =A LTC *[S e *T C *j LTC +κ*(T H -T C ) / L cell +0.5j LTC *R cell ] Among them, A LTC is the area of ​​the liquid thermal battery, S e =3.73×10 -3 VK -1 is the Seebeck coefficient, j LTC is the current of the liquid thermal battery, which is controlled by adjusting the adjustable load (204), κ = 0.4 Wm -1 K -1 is the effective thermal conductivity, T C is the temperature of the cold electrode of the liquid thermal battery, R cell is the resistance value of the liquid thermal battery, L cell is the thickness of the liquid thermal battery.

10. The small-scale distributed solar thermal power generation device based on liquid thermal battery according to claim 9, characterized in that: The performance of the power generation device can be optimized by the following parameters: The area ratio of the solar absorber (101) to the liquid thermal battery is χ = A abs / A LTC ; Thermal conductivity K con ; Thermal convection coefficient K ce ; Ambient temperature T E ; Thickness L of liquid thermal battery cell ; Among them, the maximum power density P of the power generation device and the corresponding efficiency η vary with χ=A abs / A LTC , K con and L cell increases with the increase of K ce and T E decreases with the increase of .

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