Photovoltaic-thermoelectric-water cooling three-layer coupling power generation system

Abstract

The utility model relates to a photovoltaic-thermoelectric-water cooling three-layer coupling power generation system, which comprises a photovoltaic module, a thermoelectric module and a water cooling module, the photovoltaic module comprises toughened glass, an EVA (Ethylene Vinyl Acetate) adhesive film and a photovoltaic cell layer; the thermoelectric module comprises heat-conducting silicone grease, a hot-end ceramic chip, a thermocouple and a cold-end ceramic chip; the water cooling module comprises copper water cooling radiating fins and a cooling liquid pipeline; the toughened glass is connected with the photovoltaic cell layer through an EVA (Ethylene Vinyl Acetate) adhesive film; the hot-end ceramic chip / cold-end ceramic chip is attached to the photovoltaic cell layer / water-cooling radiating fin through a layer of heat-conducting silicone grease; the temperature of the hot-end ceramic chip is transmitted by the photovoltaic cell layer irradiated by sunlight through the heat-conducting silicone grease; according to the system, sunlight energy can be utilized more efficiently. And the output power per unit area is higher than the power generated by only depending on the photovoltaic panel, so that the occupied area is saved. Therefore, the method has great potential application value in many distributed application scenes.

Description

Technical Field

[0001] The utility model relates to a photovoltaic-thermoelectric-water-cooled three-layer coupled power generation system. The system mainly uses photovoltaic materials to harvest solar energy for power generation. Secondly, thermoelectric materials are used to absorb the heat generated by solar energy from photovoltaic materials for secondary use and power generation. Finally, a water-cooled heat dissipation module is connected to the cold end of the thermoelectric material to improve the energy conversion efficiency of the overall device. It belongs to the field of solar power generation technology. Background Art

[0002] In recent years, the global energy crisis and various extreme weather events caused by climate change have jointly led to a series of economic, social and environmental problems. The fossil energy we have long relied on, such as coal, oil, and natural gas, are not only becoming increasingly depleted due to the growing energy demand, but the greenhouse gases produced by their combustion, such as carbon dioxide, have further aggravated climate change, thus posing a huge challenge to human survival.

[0003] Solar energy is one of the most abundant and accessible renewable energy sources on Earth. Photovoltaic (PV) technology can directly convert sunlight into electrical energy, which is of great significance in addressing the challenges of global energy crisis, climate change and carbon neutrality. Silicon is the most common and dominant PV cell material because it is abundant, low-cost, highly stable and has a mature manufacturing process. However, the energy conversion efficiency of silicon-based PV cells currently on the market is only about 20% at most, which means that about 80% of the solar energy will be dissipated in the form of heat energy. This heat increases the temperature of the photovoltaic panels, which not only reduces the power generation efficiency of solar cells, but also accelerates the aging of related components.

[0004] In order to further utilize the photothermal energy generated by sunlight and to cool down and increase the efficiency of solar panels, some related technical solutions focus on the development of photovoltaic-photothermal combined systems. Photothermal energy will be collected through heat-conducting media such as air, metal, and liquid, and used for heating buildings. Although this type of technology solves the problem of heat dissipation of photovoltaic panels to a certain extent, its utilization of photothermal energy is very limited, especially in the hot summer. Heating buildings will increase the energy consumption generated by indoor air conditioning cooling.

[0005] Another technical path is to superimpose semiconductor thermoelectric sheets on photovoltaic panels to convert the temperature difference between the two ends of the material caused by light heat into electric potential difference through the Seebeck effect, and then convert the thermal energy into electrical energy, thus harvesting solar energy for the second time. The thermoelectric potential generated by the Seebeck effect is,

[0006] V TE =S(T H -T C )

[0007] Where S is the Seebeck coefficient T of the material H ,T C are the temperatures of the high temperature end and the low temperature end of the thermoelectric material, respectively. Therefore, the greater the temperature difference between the two ends of the material, the greater the output voltage. For a particular thermoelectric material, its energy conversion efficiency can be expressed as,

[0008]

[0009] Where zT is the figure of merit that characterizes the thermoelectric performance of the material, which is determined by the material's Seebeck coefficient S, electrical conductivity σ, thermal conductivity κ and the average temperature T of the material.

[0010]

[0011] For a thermoelectric material component (such as a Peltier film), its zT in a specific temperature range is often determined. Therefore, in order to obtain higher energy conversion efficiency, a larger temperature difference T is required. H -T C In the scenario of combining with photovoltaic panels, the temperature of the photovoltaic panels can be regarded as the temperature of the hot end of the thermoelectric component T H ,This item is affected by natural light and working environment and is often not effectively regulated. Therefore, lowering the temperature T of the cold end c It is an effective solution to improve energy conversion efficiency.

[0012] Adding a metal heat sink to the cold end of the thermoelectric layer is a common temperature control method for this type of system. However, passive heat diffusion heat dissipation often makes it difficult to achieve a more ideal temperature control effect. In common devices that require heat dissipation (such as chips), air cooling and water cooling are better solutions to improve the heat dissipation effect.

[0013] The utility model provides a photovoltaic-thermoelectric-water-cooled, three-layer coupled power generation system. First, the outermost photovoltaic material performs the first round of harvesting sunlight to generate electricity, and the light heat generated is first harvested for the second time by the second layer of thermoelectric materials to generate electricity, and the final waste heat is removed by the bottom layer of water cooling system. Such a solar power generation module first makes great use of the heat generated by solar energy, and secondly, reliable water cooling is used to regulate the working temperature of photovoltaic materials and thermoelectric materials, thereby further improving the energy conversion efficiency of the two. Therefore, this module can greatly improve the power output of solar panels per unit area. Utility Model Content

[0014] This utility model aims to solve the problem of the waste heat generated by the photovoltaic cell system affecting the efficiency of light energy utilization and the energy conversion efficiency of the photovoltaic panel itself, and proposes a photovoltaic-thermoelectric-water-cooling three-layer coupled power generation system to achieve more efficient conversion from solar energy to electrical energy.

[0015] A photovoltaic-thermoelectric-water-cooling three-layer coupled power generation system comprises a photovoltaic module, a thermoelectric module and a water-cooling module.

[0016] The photovoltaic module includes tempered glass, EVA film, and photovoltaic cell layer. The thermoelectric module includes thermal conductive silicone grease, hot end ceramic sheet, thermocouple, and cold end ceramic sheet. The water cooling module includes copper water cooling fins and coolant pipes.

[0017] The tempered glass and the photovoltaic cell layer are connected by an EVA film; the hot-end ceramic sheet / cold-end ceramic sheet and the photovoltaic cell layer / water-cooled heat sink are bonded by a layer of thermal conductive silicone grease; the temperature of the hot-end ceramic sheet is transferred from the photovoltaic cell layer exposed to sunlight through the thermal conductive silicone grease;

[0018] The photocurrent and thermal current emitted by the photovoltaic module and the thermoelectric module will be independently connected to the MPPT controller, and then connected to the energy storage system and related inverter components.

[0019] The photocurrent and thermal current emitted by the photovoltaic module and the thermoelectric module will be independently connected to the MPPT controller, and then connected to the energy storage system and related inverter components.

[0020] The photovoltaic-thermoelectric-water-cooling three-layer coupled power generation system generates electric energy by utilizing the temperature difference between the hot-end ceramic sheet and the cold-end ceramic sheet formed by sunlight irradiation.

[0021] In the photovoltaic-thermoelectric-water-cooling three-layer coupled power generation system, the temperature of the hot-end ceramic sheet is transferred from the photovoltaic cell layer after being irradiated by sunlight through the thermal conductive silicone grease.

[0022] In the photovoltaic-thermoelectric-water-cooled three-layer coupled power generation system, the temperature of the cold-end ceramic plate is cooled by the coolant. The technical solution is to stack photovoltaic, thermoelectric, and water-cooling modules in sequence. First, the photovoltaic module located on the top layer realizes the first-stage "light-to-electricity" conversion of the incident sunlight. The part of the energy that cannot be converted into electrical energy will be converted into heat energy in the second stage by the thermoelectric module closely connected to the back panel of the photovoltaic module. The photocurrent and thermal current emitted by the photovoltaic module and the thermoelectric module will be independently connected to the MPPT controller, and connected to the energy storage system and related inverter components. The water-cooling module will be directly connected to the cold end of the thermoelectric module to dissipate heat and control the temperature of the entire system.

[0023] The technical effects and advantages of the present invention are as follows: it realizes efficient conversion of solar energy from light to electricity and heat to electricity, optimizes the heat dissipation system, and improves the overall energy conversion efficiency. In the above-mentioned photovoltaic, thermoelectric, and water-cooled three-layer stacked technical solution, firstly, the thermoelectric module effectively utilizes the heat energy enriched by the photovoltaic module, generates additional electrical energy, and improves the power generation efficiency of the overall system. Secondly, the water-cooling module effectively dissipates heat and controls the temperature of the entire system, while improving the energy conversion efficiency of the photovoltaic and thermoelectric modules, and increasing the overall power generation power of the power generation system per unit area. In some places with limited space, such as roofs, parking lots, and building exterior walls, this system can effectively increase the power generation per unit area compared to traditional photovoltaic cells. The generated electricity can not only be used for indoor electrical equipment such as air conditioning and lighting, but also the excess electricity can be connected to the grid and uploaded to obtain additional economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Shown is a schematic diagram of the power generation module structure of this system.

[0025] Figure 2 Shown is a schematic diagram of the water cooling module structure.

[0026] Figure 3 The power conversion flow chart of this system is shown as follows:

[0027] Figure 1 It contains three modules: 1. Photovoltaic module, 2. Thermoelectric module, and 3. Water cooling module. They respectively include: 1.1. Tempered glass, 1.2. EVA film, 1.3. Photovoltaic cell layer, 2.1. Thermal grease, 2.2. Hot end ceramic sheet, 2.3. Thermocouple, 2.4. Cold end ceramic sheet, 3.1. Copper water cooling fin, and 3.2. Coolant pipe.

[0028] Figure 3 It includes: a. photovoltaic panel array, b. thermoelectric array, c. water cooling heat sink array, d. mppt controller, e. central water pump controller, f. battery pack, g. inverter, h. DC load, i. AC load. DETAILED DESCRIPTION

[0029] The following is a further detailed description of the present invention with reference to the accompanying drawings:

[0030] like Figure 1As shown, the three-layer power generation component is composed of three modules: photovoltaic module 1, thermoelectric module 2, and water cooling module 3. The photovoltaic module 1 is a typical photovoltaic power generation panel structure on the market. Its top layer is low-reflection and high-transmittance tempered glass 1.1, and the middle layer is a photovoltaic cell layer 1.3. Between the photovoltaic cell layer 1.3 and the tempered glass 1.1 is an ethylene-vinyl acetate copolymer layer, that is, an EVA film 1.2, which serves as an insulating layer and protects the photovoltaic cell layer 1.3. The outer layer of the photovoltaic cell layer 1.3 will be bonded to the hot section ceramic sheet of the thermoelectric module 2 through a layer of thermal conductive silicone grease 2.1. The thermoelectric sheet is commonly composed of a large number of thermocouples 2.3 of thermoelectric pn junctions, and the p-type thermoelectric material and the n-type thermoelectric material are connected in series in a zig-zag manner through metal electrodes. The bottom is a cold end ceramic sheet 2.4, which will be bonded to the water cooling module 3 through a layer of thermal conductive silicone grease 2.1. Figure 2 The cross-sectional view of the water cooling plate in the xy plane is shown. The material of the water cooling plate is usually a copper water cooling plate 3.1 with good thermal conductivity, and a heat dissipation pipe 3.2 is arranged inside the water cooling plate to allow the coolant to flow through.

[0031] The solar energy collection process of this component is mainly divided into two parts, light-to-electric conversion and heat-to-electric conversion. When the incident sunlight shines on the photovoltaic cell layer 1.3 through the tempered glass 1.1. Through the photovoltaic effect, part of the light energy is converted into electrical energy (about 20%). This is a brief process of light-to-electric conversion. The remaining light energy will be converted into thermal energy and increase the overall temperature of the photovoltaic module. Therefore, there will be a top-to-bottom temperature gradient in the entire device, and the resulting heat flow will be transferred to the thermoelectric module 2 and the water-cooling module 3 at the bottom of the device. When the heat flow passes through the thermoelectric module, the thermoelectric pn junction will convert part of the thermal energy into electrical energy through the Seebeck effect. This is a brief process of heat-to-electric conversion.

[0032] If heat is accumulated at the cold-end ceramic sheet 2.4 of the thermoelectric module 2, it will not only increase the temperature of the cold-end ceramic sheet 2.4, resulting in a decrease in the thermoelectric conversion efficiency, but will also increase the temperature of the photovoltaic module, thereby reducing the energy conversion efficiency of the photovoltaic module. The water-cooled module 3 will effectively solve this problem. The heat accumulated at the cold-end ceramic sheet 2.4 will first diffuse rapidly to the copper water-cooled heat sink 3.1, and then be taken away from the entire system by the coolant flowing through its internal coolant pipe 3.2. This greatly reduces the temperature of the cold end of the thermoelectric material, thereby improving the efficiency of photoelectric conversion and thermoelectric conversion.

[0033] Figure 3The figure shows the flow chart of the system from the power generation end to the power consumption end. The photovoltaic panel array A, which is composed of a number of photovoltaic panels, and the thermoelectric sheet array B, which is composed of a number of thermoelectric sheets, transmit the converted electric energy to the MPPT controller D (maximum power point tracking controller, i.e., MPPT controller) to integrate it into DC power with stable voltage. On the one hand, the integrated DC power can be stored through the battery pack F, or further applied to the DC load H. On the other hand, the DC power will be converted into AC power that meets the requirements through the inverter G and transmitted to the relevant AC load i. The water-cooled heat sink array will have its internal coolant flow rate adjusted by the central water pump controller.

Claims

1. A photovoltaic-thermoelectric-water-cooling three-layer coupled power generation system, characterized in that: include: Photovoltaic modules, thermoelectric modules and water cooling modules; Photovoltaic modules, including tempered glass, EVA film, and photovoltaic cell layer; Thermoelectric module, including thermal grease, hot-end ceramic sheet, thermocouple, cold-end ceramic sheet; A water cooling module, including a copper water cooling fin and a coolant pipe; The tempered glass and the photovoltaic cell layer are connected by an EVA film; the hot-end ceramic sheet / cold-end ceramic sheet and the photovoltaic cell layer / water-cooled heat sink are bonded by a layer of thermal conductive silicone grease; the temperature of the hot-end ceramic sheet is transferred from the photovoltaic cell layer exposed to sunlight through the thermal conductive silicone grease; The photocurrent and thermal current emitted by the photovoltaic module and the thermoelectric module will be independently connected to the MPPT controller, and then connected to the energy storage system and related inverter components.

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