JP2010147129A - Photovoltaic cogeneration module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photovoltaic cogeneration module that can obtain heat simultaneously with power and solves such a problem that, at present, the solar cell's conversion efficiency for converting photovoltaic energy into power is around 12%, therefore, a required light-receiving area becomes large and the price of output power becomes high, consequently, it is difficult for solar cells to achieve practical effects compared with commercial power. <P>SOLUTION: The photovoltaic cogeneration module is configured to find out a suitable structure, suitable materials, and a suitable production method in order to combine a flat plate power generation cell, a module support substrate, and cooling piping with high strength and high productivity so as to allow them to have a heat-transfer relationship while reducing heat distortion. The photovoltaic cogeneration module is formed by combining the suitable structure, the suitable materials, and the suitable production method. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

At present, solar power generators and solar water heaters (solar heat collectors) are attracting attention not only in Japan but also overseas, reducing consumption of petroleum resources, preventing global warming, suppressing the rise in prices of petroleum resource-related components, Expansion is expected as a device system that meets other global environmental requirements and social needs. However, the scale of the market is less than 100,000 units sold every year for home use in Japan. On the other hand, there are 4 million units of gas / oil hot water supply units and 7 million units of home air conditioners.

The reason why the market scale of the single-function solar power generation device or the solar water heater itself does not increase is that the output effect is insufficient for the investment price of the device. That is, the period for collecting the initial investment (PBT) is as long as 7 years or longer, that is, it takes 30 years to recover the investment in a solar power generation device for home use, or conversely, the service life of the solar water heater is 10 years or less. This is because there are problems.
In terms of energy efficiency, the conversion efficiency (ECR) in which solar energy irradiated to the photovoltaic power generation device is converted into electric power is about 12 to 14% in a device in practical use, and the remaining energy amount 88 to 86% are not available. This requires a large-area device as an energy supply device, and the generated power cost is nearly twice as high as 23 yen / KWh, which is the cost obtained with commercial power, that is, about 40 yen / KWh. The initial investment payback period has been extended to about 40 years, which is the main reason why it has not spread. For this reason, new technology development for improving the conversion efficiency (ECR) of the power generation cell itself is expected.
For example, a 3KW solar power generation system for home use usually requires a light receiving area of 30 square meters, which not only imposes great restrictions on installation space, but also increases the price of actual installation work that is extremely difficult. It is a factor and a factor that hinders the spread.
As a result, while the commercial grid power is currently around 23 yen / KW in Japan, the output power price in the case of a solar cell alone is about 30-40 yen / KWh, assuming a lifetime of 20-25 years. For this reason, its spread has not progressed.

Therefore, recent research and development on solar power generators has been remarkable with the aim of solving these problems. Research is also progressing on the use of silicon crystal cells, such as polycrystallization, thinning of silicon crystals, improvement of power generation characteristics of crystal bodies and improvement of light reception characteristics of crystal surfaces.
In addition, a silicon amorphous material formed on a glass surface or a plastic film surface or a material obtained by laminating the silicon amorphous material with a silicon crystal has been improved. A material in which this amorphous is formed on a window glass for building materials and used as a window material for a building or the like so that the window generates electricity has been put into practical use. In addition, a material that is made of a material different from silicon such as copper or indium and deposited on a glass substrate as a cell material is also promising as an alternative to a silicon-based cell to avoid resource shortage. Solar cells using a thin aluminum plate as the cell electrode substrate have also been commercialized. This is a structure in which small spherical silicon with a diameter of about 1 mm is embedded in the mortar-shaped holes of an aluminum substrate in which a large number of mortar-shaped ridges are formed, and the surface of the mortar-shaped holes gathers in spherical silicon. It has the function of reflecting light and has the function of an electrode. This aluminum substrate electrode type power generation cell has a structure that is extremely effective for improving the performance of the solar cogeneration apparatus, which is the subject of the present invention, that the substrate is made of aluminum having good heat conductivity.
In other words, there are many types of substrates for power generation cells such as silicon itself, glass plates, resin plates, and aluminum plates.

The present invention relates to a structure of a solar module for effectively using solar energy using these power generation cells, and is used for consumer use, particularly for home use, business use, and industrial use. The present invention relates to a solar energy composite usage module (hereinafter referred to as a solar cogeneration module or a solar cogeneration module) that receives sunlight and simultaneously generates power and supplies heat.
Since several decades, research and development of solar cogeneration modules that can obtain electric power and heat with the same photoreceptor have been studied. That is, a metal plate as a heat sink is installed on the back surface of the power generation cell, and the heat generated in the power generation cell is collected through water and refrigerant in a pipe and a medium passage integrated with the metal plate. According to this method, the overall light receiving area can be reduced compared to the solar power generator and solar water heater installed separately, and the two basic effects of cost reduction and installation space reduction can be achieved. The installation work can be simplified. Furthermore, by forcibly cooling the power generation cell, the temperature of the power generation cell can be lowered, and the power generation effect of the power generation cell is improved. In addition, when used in homes and stores, there is an advantage that electric power, hot water heating temperature and heating temperature can be obtained at the same time.
The output price of the solar cogeneration module aimed by the technical field handled by the present invention can bear 50-60% of the initial price as thermal output, and the burden of output power is reduced to 40-50% of the initial price. The As a result, there is a great effect that the output power can be realized at a lower price than commercially available commercial power, that is, a price of about 20 yen / KWh.

Therefore, research efforts on this cogeneration module device have been seen in many companies, universities, research institutions, etc. from the past. However, it has not yet been realized as a product.
The reason for this is that it is difficult to ensure practical long-term reliability because it is a highly functional composite made of a complex material.
In other words, the material of the power generation cell is made of a material such as silicon or glass that has a very low coefficient of thermal expansion and poor heat transfer performance. The material has a very large linear expansion coefficient. As a result, it is practical and inexpensive to solve the demands of both the close contact structure for improving the performance and efficiency of the module and the separation structure for emphasizing reliability to cope with large thermal strain caused by a wide range of temperature changes. Feasible structure and material technology has not been established.
2. Unlike solar cells, the cogeneration module uses a material structure with high thermal insulation as much as possible around the cell and heat sink to provide the heat collection function, The temperature environment to which the structural members are exposed varies depending on whether or not the thermal energy that is the output is used, and the temperature range is extremely low, minus 20 to plus 120 ° C even in warming regions such as Japan. Due to the wide temperature range, the first problem is extremely severe.
3. On the other hand, it is a structure that circulates a cooling medium (generally water, antifreeze liquid) for using heat throughout the entire equipment system installed over a wide range, and rust due to condensation, medium leakage from the joint, There are many reliability risk items such as, and there is also a problem of the circulation pump life of the medium. Compared to solar cell systems, the practical lifetime is shortened, and there is a risk of being reduced by half.
4. The biggest problem is the risk that the power generation cell layer, the heat sink, and the cooling medium circuit body for cooling will be peeled off due to long-term use. The structure, materials, and manufacturing method to ensure long-term life as a composite structure in harsh operating environments such as snow load, wind pressure and vibration of wind, moisture, moisture, temperature change, and sunshine are not established. It is.
5. In order to solve these problems, the cost of using highly functional materials increases, the structure becomes complicated and the cost tends to increase, and the output improvement effect of cogeneration is offset. In some cases, only the same economic effect as the battery can be obtained.
There are problems as described above.

The technology of the present invention is a key element for solving the above-mentioned basic problems, and is for establishing the mechanism, structure, material, and manufacturing method of a solar cogeneration module as a key component of the system.
The technical field of the module matches the material characteristics of the power generation cell, has sufficient strength to support the entire module, heat transfer characteristics that transfer heat, and has a flat surface on which the power generation cell can be placed. A module substrate as the base of the structure and a cooling structure that can realize a long-term reliable and commercializable cost for taking out the heat generated in the power generation cell through the module substrate (in the present invention, this is a cooling structure) Further, the present invention relates to a manufacturing method capable of realizing high productivity and commercialization reliability and cost for joining a cell, a module substrate, and a cooling medium circuit body.
Technological development has been promoted with the following goals set for the cogeneration module to be realized by the present invention.
1. Achievement of high conversion efficiency in converting light irradiation energy into electric power and heat Electric power: 10-13% or more (equivalent to or better than solar cell power generation characteristics)
Heat: 40% or more (equivalent to solar water heater)
Total energy: around 50% (achieving maximum efficiency)
The goal is to achieve the above conversion efficiency.
2. Cost target: Achieve a cost increase of 25% or less compared to the solar cell module 3. Achieve the same operating life as the solar cell: 20 years or more (including repair and maintenance) 4. With the above, the solar cogeneration module As described above, the output power price is considered to be lower than the commercial grid power price, that is, 20 yen / KWh.

That is, the basic technology related to the solar cogeneration module of the present invention overcomes the above-mentioned problems by making good use of the above-described photovoltaic power generation cell itself or its material, structure, and characteristics to achieve high performance, low cost and reliability. It is related to the technical field to secure economical basic characteristics for finishing as a high solar cogeneration module and widely spreading in the market.

Conventionally, a large amount of research, development, and patent applications on solar cogeneration modules and their application systems have been carried out. However, there is no technical information at a completed level regarding sufficient performance as described above, practical cost realization, and long-term reliability. There are sporadic technical information on the pursuit of technical perfection in these three aspects, so we will introduce it here as background technology.
Against this background, many researches and developments have been made on the technology of the solar cogeneration device for simultaneously obtaining heat from the solar power generation device.
Among them, Patent Document 1 proposes a technique regarding a cooling method using a primary refrigerant based on a combination of a heat collecting panel and a heat collector. However, the power generation cell dissipates heat through the EVA resin and the transparent glass substrate, so that the amount of heat gained is greatly reduced. Further, since the refrigerant passage is formed by bonding or welding the upper heat collecting plate and the lower heat collecting plate, the risk of refrigerant leakage is great. If a leak occurs even at one of many panels after installation on the roof, there is a risk that the product value will be ruined due to the difficulty of discovery and repair, and it cannot be adopted. There is no ingenuity on mitigating thermal strain on the power generation cell of the upper heat collecting plate made of aluminum, and there is a great risk of damage to the power generation cell and failure due to repeated heat cycles during long-term use. Since the upper heat collecting plate and the lower heat collecting plate have an aluminum block structure, the weight of the upper heat collecting plate and the lower heat collecting plate increases, and there is a problem of installation workability in terms of cost increase and weight increase. In view of the above, commercialization is very difficult with such a structure.
Patent Document 2 presents the basic structure of a cogeneration module, but the heat loss through the glass from the top surface of the cell decisively degrades the performance, and the components that serve as the basis for ensuring the planar strength of the entire module are Without white glass and heat collector, the overall strength is insufficient with respect to loads such as wind pressure vibration due to snow and typhoons, etc., the heat collecting plate is cut into pieces, and the reliability of joint strength such as EVA film that adheres to the film The property deteriorates remarkably and can be peeled off after several years of use. In addition, each EVA bonding is thermally welded in a separate process, and there is a concern about a decrease in productivity and quality compared to a method in which the whole is bonded by a single heating operation.

Patent Document 3 is excellent in that the planar metal plate serves as a support, that is, the entire base and maintains strength and shape accuracy. However, the structure in which the corrugated metal plate is welded to the flat metal plate to form a water passage and is connected to the header pipe has many welding points, and its manufacturing reliability is due to the occurrence of leakage of the cooling medium of the module. It is a risk. There are many worries about various factors during production, long-term external force such as typhoon, and rust caused by rain, moisture and air pollution. Considering the installation conditions that are difficult to repair on the roof, etc. and the fact that it is a device that guarantees long-term operation for 20 to 30 years by installing a large number of modules of a very large area, and further deformation of the flat metal plate by this welding There is also a risk of damage or breakage of the cell due to the occurrence of unevenness on the surface, and it cannot be said that the structure can be adopted.

Nonetheless, it is worth considering adopting a method in which the whole is integrally bonded by a vacuum laminator.
In Patent Document 4, a back sheet made of an aluminum plate is provided on the back surface of the photovoltaic power generation cell, and a heat collecting plate for pressing the heat collecting tube is bonded to the back sheet. The heat collecting plate is mechanically pressed by a pin and bonded. Since the heat collecting plate made of small metal pieces is small, the adhesion easily peels off from the end face when the module vibrates due to wind pressure due to a typhoon or the like. In order to prevent this, the method of mechanically fixing the back sheet with a metal pin contributes to a certain degree of strength and reliability improvement, but it is considered difficult to completely prevent peeling. In addition, a large number of heat collection tubes are connected to the header tube by brazing, and the risk of leakage of the cooling medium from this portion is large and can be said to be an unstable structure. In addition, the above-described adhesive bonding with pins requires a lot of labor and bonding time in the manufacturing process, and it is considered that the deterioration of productivity leads to an increase in manufacturing cost.

Although the details have been described above, it can be seen that many problems remain to be achieved in the conventional technology. This is because the solar module which is the subject of the present invention is composed of a large number of modules having a large area, so that it is important to be easy to install and repair on a roof or the like, and to operate for more than 20 years. This is because many characteristics that should be provided are necessary as equipment for which guarantee is required. Furthermore, a lot of ingenuity is necessary to achieve the cost of being able to sell products at a practical price with high productivity and high reliability as a product, and many technologies related to the structure, materials and manufacturing methods necessary for that purpose have been established. It must be.

Japanese Laid-Open Patent Publication No. 10-62017 JP 2003-234491 A JP 2002-39631 A Japanese Laid-Open Patent Publication No. 2005-214430

Summarizing the above contents as a study topic, the important items are organized as follows. That is, the following characteristics are required for the structure and material for putting the solar cogeneration module into a commercial product with a high commercial value installed in a limited space such as a home or a store.
(1) Structural strength Power generation cells and cooling mechanisms are stably and firmly held, and structures, joints, and materials that can withstand stresses such as snowfall, earthquakes, typhoons, and deformation distortion of the entire system are required. For this reason, it is considered that the cooling mechanism itself has a high strength, or a high-strength substrate-like structure is necessary. This strength member is not only strong, but must be made of a material resistant to rust, light weight, and low cost.
(2) Flatness The upper surface of the strength member or the substrate needs to be a highly accurate plane in order to support the power generating cell that is easily broken.
(3) Thermal strain Since this strength member or substrate is bonded in a thermal contact with the power generation cell material, it is also important to be able to cope with stress strain caused by thermal strain caused by temperature change. That is, silicon crystal and glass are materials that have a very small linear expansion coefficient with respect to temperature changes (2.7 to 3.5 / million / ° C.), whereas in aluminum, deformation due to thermal strain more than ten times occurs. Therefore, the difference in strain must be relaxed and still thermal bonding must be maintained.
(4) Heat transfer performance When taking out the heat generated in the power generation cell, it is necessary to bring the power generation cell and the cooling mechanism in close contact as much as possible. It must be a structure and material that can be absorbed. Copper, aluminum, iron, glass, and resin are excellent in heat conduction in that order, while resin, aluminum, copper, iron, glass, and silicon substrate have high thermal expansion coefficients in that order. Utilizing these characteristics, it is necessary to use structures and materials that efficiently extract heat and absorb mutual thermal strain.

(5) Cooling medium leakage and long-term reliability of the cooling circuit Water and antifreeze are used as the cooling medium, but this medium is stable and free of leakage over a period of 20 years, which is equivalent to the operating life of the power generation cell. In order to operate, a cooling mechanism with a simplified structure and a structure of a cooling medium circuit constituting the cooling mechanism are required. Basically, it is desirable to use a metal material that can withstand long-term use without welding or joining. The welded structure of two plates cannot be adopted from the viewpoint that it is most important to prevent leakage, no matter how accurate the welding is. As a method for solving the problem of rusting of the cooling pipe, a method of making the cooling circuit made of resin is also effective. There is a problem of extremely small (0.3 W / m ° C).
(6) Reliability of joining the power generation cell to the cooling pipe There are many ways to join the cooling pipe to the module board, such as brazing and bonding. However, the simple way to join the pipe to the board is the transmission within the board. No suitable method can be found from the viewpoints of thermal characteristics, heat transfer characteristics around the cooling pipe, peeling of the joint, deformation of the substrate, etc. As described below, this part is made of aluminum, which serves as a cover material for the bottom surface for hot-melt bonding and effectively transfers heat from the substrate to the cooling pipe, and is lightweight and low-cost. A method such as covering with a thin plate is suitable. The shape should also satisfy the needs as detailed below.
The module substrate is sandwiched between the power generation cell, the cooling pipe, and its cover material in a state where heat can be transferred, and there is no peeling or material damage due to the difference in the amount of thermal strain between the materials. Bonding by a bonding method with excellent productivity and superior manufacturing cost is required.

(7) Heat resistance and weather resistance The operating environment of the module is a temperature range: -20 ° C to 50 ° C, a humidity range: 10 to 100%,
Wind speed: 40 m / sec is assumed. The maximum module temperature when operating under these environmental conditions is about 125 ° C when the cooling medium function stops. The reason for this high temperature is to reinforce the heat insulation of the upper and lower surfaces and the outer periphery as a thermal collector.
Sufficient security measures must be taken for freezing in a low temperature environment close to -20 ° C.
(8) Productivity The problem is related to the joining of the power generation cell and the cooling medium circuit body. Adopting a complicated manufacturing method to ensure the reliability mentioned above increases the cost and must be avoided. Since a module uses a large number of modules, the productivity of its production needs to be refined much more than that of a normal single device.

(9) Costs and material costs Development of structures, materials and manufacturing methods that meet the above functional requirements requires advanced technology and makes it difficult to put into practical use. Furthermore, since those that satisfy these functions are highly functional in terms of their materials and structure, their costs increase, making it difficult to put them into practical use as consumer devices.
(10) Manufacturing equipment investment Cogeneration modules tend to have a complex structure for realizing multiple functions, and the manufacturing process usually requires several processes, and the manufacturing equipment investment for that is large. Higher costs and increased initial capital investment are barriers to business participation.
As described above, various techniques of the present invention have been researched and studied with the aim of realizing successful development of modules satisfying (1) to (10).

The module structure, material, and manufacturing method that can solve all the above problems have not been clarified so far. Summarizing these, the following three items are important as the target issues for the solar cogeneration module, and the technology of the present application is also aimed at realizing a module aiming at this.
(A) As an output energy target, electric power is equivalent to that of a solar cell alone, and thermal performance is equivalent to that of a solar water heater alone.
(B) Achieve 20 years of operating life and 30 years assuming service maintenance.
(C) 20-30% cost increase as a module cost based on single function solar cell
The target is below.
This is because the set values of the above target tasks are estimated to be able to achieve the maximum target of halving the output energy price by realizing this.

The module structural method targeted by the present invention is that the power generation cell is installed directly or indirectly on a metal module substrate (heat sink flat plate), and the heat generated in the power generation cell is not dissipated to the surroundings. The solar energy recovery rate is increased by transferring heat to the heat sink plate to obtain a high recovery rate of around 50%, while the solar cell has a recovery rate of around 12%. I can do things.
Therefore, in the case of a home cogeneration apparatus, a practical effect can be satisfied even if the total light receiving area is reduced to about 10 to 15 square meters as compared with a single photovoltaic cell system (about 30 square meters). On the other hand, the light receiving area of the conventional solar water heater is larger than that of 4 to 6 square meters, but it has a power output, and the amount of heat obtained is sufficient, so it can be used not only for hot water supply but also for heating. It is advantageous that the utility value of the output energy is high.

Claim 1 presents a basic technical concept for solving the above-mentioned many problem items. The basis of the technology concept is a structure in which a very strong flat plate structure can be obtained by the structure of the solar cell core solidified in seven layers around a metal module substrate, and the structure is uniformly bonded over the entire plane area. Is to ensure extremely high reliability against peeling of the joint and high heat transfer performance. At the same time, it has presented many technical ideas that can achieve high manufacturing productivity, simplified manufacturing equipment, and reduced product cost.
This solar cogeneration module is installed on the roof of a house, etc., and is configured as a flat plate as a whole, and fixed on the roof or the like with a fixing angle or the like.
However, the assembly of power generation cells that constitute the solar cell that forms the core of this module refers to a configuration in which individual power generation cells are connected by electric leads. The power generation cell is called a bulk silicon, which is a thin plate of silicon crystal, a so-called CISG in which a metal layer such as copper, indium, selenium or gallium is deposited on a glass plate to form a battery layer, or a thin resin Many types of materials such as amorphous silicon or dye-sensitized type formed in the form of a paint film on the surface of the material, and the so-called spherical silicon type in which the above-mentioned extremely small spherical silicon sphere is mounted on an aluminum substrate There is. Here, the assembly of the power generation cells means a thin plate-like structure in which a large number of these cells are arranged and electrically connected to maintain the solar cell function as a whole.

The cell upper surface cover is a lid for holding the power cell assembly and protecting it from the outside. It is attached to the upper surface of the power cell assembly with a bonding resin such as ethylene vinyl acetate copolymer resin (EVA), so that moisture and environmental air can be used. In addition to protecting it from the gas inside, the power generation cell assembly is structurally maintained. Transparent and chemically stable to sunlight, and flexible and flexible materials like films are used, but glass plates are sometimes used, but usually chemically stable fluorine-based resin films are used. There are many things. This cell upper surface cover is pre-bonded with or integrated with heat-responsive bonding resin laminated on the upper surface of the power generation cell assembly, or surface treatment that provides moisture resistance and weather resistance to the surface. Of course, it is possible to omit the use by using a heat-responsive bonding resin that has been subjected to or has been provided with moisture resistance and weather resistance. In that case, the solar cell core has six layers.

The metal module substrate is a flat metal plate that is placed between the power generation cell assembly and the cooling medium circuit body, and is supported on the upper and lower surfaces to form a solar cell core. . Of course, it is important that the power generation cell is bulk silicon that is easy to break, and that the flatness, distortion, and deformation of the surfaces of the members to be joined are important. is there.
As the material, an iron plate, an aluminum plate, a SUS plate, a surface coated or plated one thereof, a resin coated one, or the like is used. The thickness is selected from about 0.5 mm to 1.2 mm in consideration of strength, weight, cost, and the like. For the surface treatment, an optimum treatment method is selected in consideration of long-term reliability such as improvement in absorption characteristics of received light, electrical insulation, and rust.

The material of the module substrate is selected mainly considering three points of cost reduction, heat transfer performance, and thermal strain characteristic evaluation with the power generation cell. One of the reasons for the proposal of the present invention in which the module substrate and the cooling medium circuit are configured as separate parts without being integrated is that a module substrate material optimum for the type of power generation cell can be freely selected. The second reason for using the module substrate separately from the cooling medium circuit is that it is easy to make the top surface completely flat, so that deformation and distortion to the cell when the power generation cell is mounted can be minimized. is there.

The cooling medium circuit body is entirely flat and contains a cooling medium circuit that circulates water and antifreeze liquid (propylene glycol aqueous solution), which is the cooling medium, and collects heat from the power generation cell and metallic module substrate. There are various structural methods. For example, it is made of resin, has a flat upper surface and a medium flow path is formed inside, and a cooling medium flows therethrough, or a lower surface formed by pressing a cooling medium circuit on an upper flat plate made of two SUS plates The one formed by welding the plates of the cooling medium circuit, the one using the aluminum extruded flat plate having a number of pipes formed therein, the one using the aluminum thin plate and the pipe shown in claim 2, etc. is there. In any case, a structural material having a flat upper surface and good thermal conductivity is selected. The most important evaluation criterion is to reduce the leakage failure of the cooling medium and the peeling failure between the module substrates and to have sufficient reliability even after use for more than 20 years, but the manufacturing cost and high production It is also important to preserve sex.

The above-described structure system in which the cell upper surface cover, the power generation cell assembly, the metal module substrate, and the cooling medium circuit body described above are laminated in a flat shape and are joined to each other and integrated. It is an idea that becomes the foundation of
A strong integrated body can be constructed by joining together as a seven-layer planar structure in which three layers of bonding resin films are sandwiched between the above four flat plate-like members. Here, it is called a solar cell core. As described above, the solar cell core is a flat plate made of seven layers of members having substantially the same area.

Ethylene-vinyl acetate copolymer resin (EVA) is a heat-responsive bonding resin that is transparent and softens at about 150 ° C to cross-link and harden to exhibit the bonding function. A film such as ethylene methyl methacrylate copolymer resin (EMMA) is used. The power generation cell is sealed, fixed, and held by the bonding resin and the heat-responsive bonding resin having similar characteristics arranged on the lower surface of the power generation cell assembly.

The bonding resin on the lower surface of the power generation cell assembly is not required to be transparent as in the case of the EVA described above, but since it requires electrical insulation with the metal module substrate, an insulating resin film is laminated in a sandwich shape. Instead of using an EVA film or an insulating resin film, a module substrate in which an insulating resin is coated on the surface of a metal flat plate may be used.
A heat-responsive bonding resin is also used for bonding the module substrate and the cooling medium circuit body. The above-described transparent EVA may be used, or a heat-responsive resin film that is not necessarily transparent may be used.

The three-layer heat-responsive bonding resin described above is laminated in seven layers by placing it in a sandwich between the four-layer members described above. This is installed in a lamination treatment tank and heated to about 150 ° C. for several tens of minutes to create a vacuum environment, so that the heat-responsive bonding resin dissolves and fills between the layers and crosslinks. Join the four-layer members. Since the bonding resin EVA retains flexibility like a hard rubber even after it has been cross-linked and hardened, the cell upper surface cover, the power generation cell, the module substrate, and the cooling medium circuit are firmly bonded to each other without being fixed to each other. To do. Accordingly, the thermal strain between the above four members is absorbed and relaxed to prevent problems such as deformation, breakage of the warped cell, and peeling of the joint.

As described above, the bonding resin is flexible even after being fixed, and a sufficient thickness is generated in the power generation cell to play a role as a buffer between strain and stress between the four members. In order to efficiently transfer the solar heat to the cooling medium in the cooling medium circuit through the entire plane area, a thin wall thickness is required so as not to hinder the heat transfer. is important. In the case of EVA, a wall thickness of about 0.2 to 0.8 mm is practically selected.
The joining work of the present invention is characterized in that it can be realized by performing only a laminating work and, if necessary, a heat retaining work for crosslinking or both. Conventionally, the cooling medium circuit body and the module substrate are usually joined by screw occupancy, welding, brazing, chemical bonding, or the like, and the power generation cell assembly and the module substrate are usually joined by EVA hot melt joining.

The important thing is that the above three-layer joining can be completed by one processing step. In addition to avoiding deformation of parts and work mistakes due to various types of processing such as bonding, welding, brazing, screw tightening, etc., which are performed in the case of normal joining and joining processing, high production is also avoided. This has extremely important advantages in commercialization and commercialization, in which the capital investment for manufacturing can be minimized, as well as the reduction of the manufacturing cost and the manufacturing cost.
Thus, the solar cell core as a seven-layer structure as a whole can be manufactured by the simplest method.
The seven-layer solar cell core has the following features due to its manufacturing characteristics.
The strength is high because of the three-dimensional structure of 1 and 7 layers.
2. Excellent heat transfer characteristics because all joint surfaces are in close contact.
3. Since the bonding resin layer is interposed in one layer, it has a function of relieving mutual thermal strain, and in particular, the presence of a layer called a module substrate makes it possible to select and use a metal material optimal for buffering thermal strain.
4. Since the entire area is bonded, it is highly reliable against peeling due to the vacuum effect.
5. Productivity is high and manufacturing equipment investment is small.
6. Since the members of the intermediate layer can be completely isolated from the outside world, rust, deterioration, etc. can be prevented.
7. There are no other joining processes such as welding and screw occupation, the risk of manufacturing defects is small, and it is easy to improve the reliability of long-term use of products.
8. Assembling by heat treatment joining, the structure, material, shape, etc. of the members to be joined can be freely selected, and the optimum combination is possible.
9. As a result, the cost is superior.
It is possible to obtain extremely superior results in commercialization.

Therefore, it is possible to guarantee long-term reliability as equipment that is expected to have an operating life of 30 years or more under severe operating environment conditions.
Furthermore, it is possible to further improve the reliability by sealing the outer peripheral portion of the solar cell core completed by joining with a weather-resistant paint.

(2) One pipe In claim 2, as the cooling medium circuit body, in order to output the heat, one metal cooling pipe is bent and embedded in a recess formed on the upper surface of the metal cooling pipe cover. A cooling medium circuit body in which both surfaces are combined so that the upper surface is substantially flat is presented. Here, one cooling pipe is based on the premise that a copper pipe, an aluminum pipe or a SUS pipe, which is a metal pipe, is used as a flow path for a cooling medium used in one solar cogeneration module.
As a cooling medium circuit body, for example, a plate-like structure made of resin and having a cooling medium circuit inside, a type in which two stainless steel plates are welded and a cooling medium flows between them, and an aluminum plate with a flat top surface Many methods have been proposed, such as a cooling medium circuit configured in the matrix. However, the aim of the present invention is to achieve both long-term reliability and long-term reliability of modules installed on the roof, and it is lightweight and easy to install. It is absolutely necessary that the cooling medium never leaks even if it is used. Therefore, it is considered unsuitable for products that cannot completely eliminate deterioration due to manufacturing errors or long-term use, such as those in which a cooling medium circuit is formed by welding a resin and a metal plate that are likely to deteriorate after long-term use. This is because if a leak occurs even at one location, the entire system will malfunction and there is a risk of inconvenience to the user during repair service. The inventor's conclusion and the basis of the basic technology is that the cooling medium system that meets the purpose should be constructed using a single continuous metal cooling pipe.

Of course, in claim 2, it is possible to connect and use two copper cooling pipes in the middle.
This is because it is basically included in the concept of this basic technology. In order to thermally and structurally join these continuous cooling pipes to the flat module board, the cooling pipe cover, which is a thin aluminum plate, covers the lower surface of the pipe to cover the upper module board. Presents a method of joining. This cooling pipe cover uses a thin plate with a thickness of 0.4 mm to 1.2 mm from the viewpoint of productivity, product weight, joining reliability, cost, etc., and makes the joining surface flat throughout, The above requirement is achieved by a structure in which a cooling pipe is embedded in a place where a concave portion is formed by forming an aluminum thin plate so that the upper surfaces of both companies are flat.
By adopting this structural cooling medium circuit body in the solar cell core presented in claim 1, the basic concept of a practical solar cogeneration module which is the object of the present invention is completed.

Claim 3 presents a technique for thermally and structurally joining the cooling pipe and the cooling pipe cover shown in claim 2. Of course, it is effective to carry out the joining of this portion simultaneously with the joining of the seven layers described above. Therefore, an EVA film or the like is also sandwiched in the gap between the cooling pipe and the cooling pipe cover as a heat-responsive bonding resin, and is bonded simultaneously. By this method, it is possible to achieve high productivity, high overall joining reliability, absorption relaxation of thermal strain in the cooling pipe, low cost, and the like.

Claim 4 presents the overall configuration of the solar cogeneration module.
The module upper surface cover covers the upper surface of the flat solar cogeneration module, and is a light transmissive flat plate for covering and maintaining the module from rain, wind, and the outside. The air layer between the solar cell core underneath is a space provided in order to minimize the heat dissipation loss from the module, and an air space having a thickness of about 30 mm, which is usually close to a sealed state, is often provided. Even if a thicker air layer is provided, the effect of reducing heat dissipation loss is small, the size of the module increases, the cost increases, and the shade of sunlight by the frame reduces the power generation and heat generation efficiency of the power generation cell. End up. Therefore, it is effective to install a reflector that reflects the light that also functions to connect and fix the module top cover and the module substrate inside the frame on the outer periphery of the air space that becomes the upper heat insulating layer. is there. It is practical to design the inclination angle between 45 degrees and 75 degrees with respect to the power generation cell surface.

The lower heat insulating layer also reduces heat loss and has an important function as a cover material for the lower surface. Usually, a foamed resin heat insulating material having a thickness of 20 to 30 mm is used. A urethane foam sheet with a polyethylene cover sheet on the lower surface is suitable.
The frame covers and holds the outer periphery of the top cover, solar cell core, and lower heat insulating layer. Resin, aluminum, SUS, etc. are excellent. It is important to support and hold the entire module and to reduce the protruding size from the top cover so as not to disturb the snow that accumulates on the top cover due to snowfall. Therefore, a structural design that eliminates the protrusion from the top cover is required.
The simple overall structure shown in claim 4 is a practical technology that is extremely important in ensuring system performance, ensuring operational reliability, and reducing costs.

Claims 5 and 6 are basic techniques relating to material selection of the module substrate.
The main members of the power generation cell are defined as follows. When a flat bulk silicon crystal cell is connected in a circuit with a lead wire, a silicon crystal is a main member. In the case where a metal compound is deposited on a glass substrate, the power generation cell is a metal compound, but the main member is a glass substrate. A resin plate is a main member of a resin plate coated with a power generation cell material. In the spherical cell system in which an infinite number of spherical silicon crystals are arranged on an aluminum substrate, an aluminum plate is a main member. The main member means a member to be a base bonded to the module substrate.

The techniques shown in claims 5 and 6 are advantageous in terms of cost, mainly by combining the materials with the smallest possible thermal strain when the main member and the module substrate are joined together, and at the same time without impairing the heat transfer characteristics. This is a technique for selecting a suitable material.
That is, when the power generation cell is made of glass or silicon (the linear expansion coefficient is the second power of 2 to 5 × 10), the linear expansion coefficient EC is small, so that the smallest EC is a practical metal material such as an iron plate, steel plate, and stainless steel. An iron plate (EC = 12-18 × 10 6) is used. By using a material having a similar linear expansion coefficient, the strain stress generated in the power generation cell can be reduced, and the occurrence of cracks, disconnections, and warpage can be prevented. In that sense, when the substrate of the power generation cell is aluminum (EC = 24 × 10 6) or resin (EC = 20 to 90 × 10 6), the metal with the largest EC is practical metal material. It is recommended to use it.

In the case of a power generation cell using bulk silicon, an iron plate having a thickness of 0.5 t to 1.0 t is used for the module substrate. This thickness is determined in consideration of the pressure resistance to withstand snow, etc., reducing the total weight of the module, and reducing costs. In the case of an iron plate, it is possible to obtain points for each evaluation item of thermal conductivity, thermal strain, flatness, strength, and workability, and the most important advantage is that the material price is low. In fact, when using an iron plate for the module substrate, there is a concern about the occurrence of rust on the assumption that it will be used for a long period of time, and painting or resin coating is applied to ensure insulation from the power generation cell. It is desirable to prevent this by plating. Similarly, when aluminum is used as shown in claim 6, it is desirable to use a resin film coated or anodized or painted on the surface in consideration of the biographical insulation.

As shown in claim 7, when a rust-resistant metal material such as an iron plate is used for the module substrate, the entire substrate is buried in a sandwiched resin film such as EVA sandwiched so that it does not come into contact with outside air. It can be devised so as not to cause deterioration due to. In this case, the planar shape dimensions of the module board made of iron plate are made small so that the upper and lower surfaces are completely covered with the bonding resin. With this technology, it is possible to prevent deterioration due to rust, which is the biggest problem, using the cheapest iron plate having excellent characteristics as a module substrate.
However, when an iron plate or a stainless steel plate is used as a module substrate, it is necessary to design in consideration of the poor heat conduction as the material. In the case of an aluminum plate (thickness 2 mm), heat transfer is good if the cooling pipe is thermally joined to the back of the aluminum plate with a wide pitch interval of about 100 mm, but in the case of an iron plate (thickness 2 mm). It is necessary to increase the number of cooling pipes, such as by installing them at narrow pitch intervals. If possible, it is desirable to directly cool the entire lower surface of the module substrate with a cooling medium. This is a problem of how to increase the contact area of the cooling medium to the module substrate. Flowing the entire surface of the lower surface of the module substrate in contact with the cooling medium is problematic in terms of structure and cost. Therefore, the proposer needs to simulate how much area should be cooled and perform test evaluation to optimize the pitch of the cooling pipe.

The temperature difference generated between the power generation cell temperature and the cooling medium is the short distance width dimension L of the non-cooling area when the portion where the cooling medium does not flow, i.e., the portion where the cooling medium does not directly cool is set as the non-cooling area. In the case of a cooling pipe, it is proportional to the square of the adjacent cooling pipe pitch dimension minus the pipe diameter dimension) and inversely proportional to the heat sink plate thickness. In the case of an iron plate having a thickness of 1 mm that is actually adopted, for example, sunlight has an illuminance of 1 KW / 1 square meter (when sunlight is received at a right angle during the day), and the amount of heat corresponding to 40% of that is used as a cooling medium. If the short distance dimension L is 40 mm when absorbing, the temperature difference will be about 5 ° C. Therefore, unless the maximum short distance dimension is set to 50 mm or less, the temperature difference is the performance of the entire system. This is because it will be fatal. If the diameter of the cooling pipe is increased in order to reduce the shortest distance dimension L, the material cost increases, the flow rate of the cooling medium in the pipe decreases, the cooling effect on the medium side decreases, and the cooling medium is enclosed. Since the required amount increases too much, the problem of an increase in the amount of the entire system enclosed, and in the case of water, it becomes difficult to prevent freezing, etc. must be avoided.

In order to reduce the material cost, it is an effective means to form the circuit through which the cooling medium flows with resin in order to widen the circuit. In this case, the resin-molded cooling medium circuit is bonded to the lower surface of the iron plate or stainless steel plate. Resins generally have a large coefficient of linear expansion, so there is a concern that the strain size difference will concentrate on the bonded part due to temperature changes of iron plates and stainless steel plates, and the entire solar cell core will be deformed by temperature changes. It is necessary to pay attention to it. In order to prevent this, it is effective to mix glass wool fiber or carbon fiber into the resin to reduce the linear expansion coefficient, or to make the structure of the resin cooling medium circuit to absorb thermal strain.

The technique presented in claim 8 relates to a method of bonding or brazing a cooling pipe formed flat so that the joint surface coincides with the lower surface of the module substrate. A technique for processing the end face of the cooling pipe to be flat has already been proposed. In this case, the flat surface formed on the cooling pipe is just flush with the flat surface of the cooling pipe cover when the cooling pipe is incorporated into the cooling pipe cover described above, and the cooling pipe and the cooling pipe cover are joined together to form a flat surface for joining. It is effective to configure. As a result, it is possible to join the entire surface with the module substrate, and the flat surface formed on the cooling pipe functions as a direct heat transfer surface, and the heat transferred to the cooling pipe cover is semicircular. It is possible to receive through, and ideal heat transfer characteristics are obtained.

The tenth aspect relates to the shape of the flat surface of the cooling pipe. As an example, there is a method of securing or flattening a flat surface by making the cross section into a cross-sectional shape and bonding or brazing the whole to a meandering shape. It is important to provide data information on how to secure the bonding area, that is, what ratio should be set in the circumferential direction with respect to the total outer circumferential length. This is because securing the area of the joining surface is extremely important in terms of securing the heat transfer area as well as increasing the certainty of joining. Considering the ratio of the joint surface in the circumferential direction to the entire outer periphery, if 50%, the piping is completely crushed and the cooling medium does not flow. At 38.9%, the pipe is completely semicircular. If the flow path area of the cooling medium is regarded as important, this value should be selected to be 30% or more, and a semicircular shape of about 38.9% is desirable in the idea of securing a bonding area with the module substrate. Furthermore, considering the heat conduction in the module substrate, it is effective to set the flat surface width large, but if it is 42% or more, the piping material becomes too high. Considering all the above considerations, it is desirable that the ratio is 30% or more and 42% or less. If it is 40% or more, the pipe line becomes extremely flat and the area of the joint to the module substrate becomes large, which is advantageous in terms of performance. However, the material cost is limited. Actually, it is practical to set the ratio in the range of 30 to 42% as a flat surface.

    It is also effective to select a resin or stainless steel pipe that is resistant to rust against water as the cooling pipe, and an iron pipe, stainless steel pipe, or aluminum pipe lined with resin for rust prevention on the inner surface. If the module substrate is an iron plate, the coefficient of linear expansion is 12.1 (× 1 / million / ° C.), and glass 3.5 to 10.0 (same) or silicon compared to aluminum 24.0 (same). The value is close to 2.7 (same) as that of the crystal, and the stress due to thermal strain is relieved considerably. In that case, it is desirable to select a material having the same linear expansion coefficient for the cooling pipe. As described above, when the cooling pipe, the cooling medium circuit, the cooling medium circuit cover, and the like are bonded to the module substrate with an adhesive or the like, it is desirable to fix them mechanically in order to prevent subsequent peeling and deformation. Therefore, when the power generation cell is bonded to the upper surface of the module substrate, it is practical to mechanically fix the module substrate and the cooling pipe or the like at the portion where the power generation cell is not present, that is, the outer periphery of the module substrate. Mechanical fixing may be a method of screwing using a fixing band.

Claim 9 presents a technique relating to the combination of the metal material of the module substrate and the material of the cooling pipe. The reason for this combination is to use materials with similar linear expansion coefficients in order to reduce thermal distortion and to reduce the cost. The reason for using a cooling tube of an aluminum tube and a resin tube is cost reduction. In order to prevent the aluminum tube from being corroded by the cooling medium, the inner surface thereof is lined with polyethylene resin or the like.
As described above with respect to the second aspect, it is important to use a cooling pipe cover having a large area as much as possible to ensure a sealed state of the resin joint surface in order to prevent joint peeling. However, the reason why the cover thin plate is divided into 2 to 9 sheets instead of one sheet is a device for absorbing thermal strain due to temperature change. In particular, a device for absorbing thermal strain is indispensable in the longitudinal direction of the cooling pipe, and in that direction, the cooling pipe cover must be divided into two or more. This parting line is a parting line, but it may be partly cut by cutting most of the part other than the connecting part, or may be formed by forming an angled bead for absorbing stress strain in a line shape. .

It is important to maintain the reliability of the part to be cut off from the bonding resin of air and humidity by painting or tape sticking, and the part to be cut is sealed with tape before heat bonding. If this is done, it is possible to prevent the bonding resin from melting and protruding. At the time of heat joining, the aluminum plate of the cooling pipe cover expands greatly, and when the joint plate is cooled to a normal temperature after the joining is completed, a gap line is formed on the aforementioned sectional surface. Usually, it is a line with a gap of about 0.5 mm. Therefore, when exposed to a high temperature during the actual operation, the gap provides a margin for the expansion allowance for absorbing thermal strain.

When water is passed through the cooling pipe, the temperature of the power generation cell, the module substrate, the cooling pipe, etc. may rise to 120 ° C. or higher when the water pump breaks down in the summer high temperature environment. In this case, the heat resistance of the resin or adhesive is severe. On the other hand, there is radiation cooling such as midnight in the severe cold season, and heat is radiated from the cell, and both the module substrate and the cooling pipe are lowered to 0 ° C. or lower. At this time, there is a concern that the cooling pipe cover, the module substrate, the power generation cell, etc. may be damaged due to the freezing of water in the cooling pipe, and the defect such as peeling of the adhesive joint portion may occur. In order to prevent this, the structure around the cooling pipe is important. When the temperature rises during the heat wave, the water in the cooling pipe evaporates and exhibits the effect of suppressing the temperature rise. In order to adopt a system in which the generated steam is raised in the cooling pipe by natural convection and exhausted, it is important that there is no space for gas accumulation inside the cooling pipe. For example, if all the parts of the cooling pipe are formed in a meandering climbing slope, the generated water vapor rises to the top and is exhausted to the outside through the exhaust steam mechanism.

As a result, the inside of the cooling pipe is always filled with water, so that it can be kept below 100 degrees plus a slight temperature rise. On the other hand, in the severe cold season, water in the module is prevented from freezing by a faucet built in the antifreeze piece provided below the outside of the module. The faucet communicates with the inside of the cooling pipe of the module. When the outside air temperature drops and the piece portion of the faucet becomes 1 to 2 ° C. or less, the piece is opened and drained from the faucet. Although the amount of this drainage is small, the water in the cooling pipe of the module is circulated and freezing can be prevented. Of course, if the temperature of the piece rises, the faucet will be closed, so the amount of water drained can be slightly reduced depending on the insulation of the module. In this case as well, it is important that there is no pool of water in the cooling pipe and that all the contained water can flow down little by little.
For this reason, the cooling medium is introduced from the lowermost part of the cooling pipe and discharged from the uppermost part, and the structure of the cooling pipe must always be horizontal or ascending from the bottom to the top. is there.

The abnormal temperature rise described above is directly caused by the provision of the heat insulating layers on the upper surface and the lower surface of the solar cell core as described in the description of claim 4. Therefore, it is effective to provide a cooling ventilation path in any one of the heat insulation layers, provide a minimum necessary ventilation hole at the lower end thereof, and install a temperature detection type opening / closing door at the top. An effective method is to provide the door at the uppermost end of the module board and use an air layer as the upper heat insulating layer for the cooling air passage. A temperature detection type open / close door is automatically opened and closed by a spring mechanism linked to a bimetal thermo so that it opens at around 90 ° C. and closes at a temperature of about 75 ° C. The above open / close temperature specification is determined on the assumption that the heat resistant specification limit temperature of the bonding resin or the like is 100 ° C. or higher and the output thermal temperature during normal operation of the cogeneration module is set to about 60 ° C. at the maximum.

The following effects are considered to be obtained by the present invention.
1. Present the basic method and basic technology for the construction of a solar cogeneration module that has the function (cogeneration) to simultaneously acquire power and heat from the same cell using sunlight. Made possible.
2. Clarified the structure, materials and other basic technologies required for the design and manufacture of solar cogeneration modules.
3. The technology presented in the present invention can realize a high-performance and practical solar cogeneration module with high reliability, long life, high productivity and cost response capability.
4. It is possible to make a prospect of realizing a distributed energy utilization system incorporating this module, and studies for realizing this system can be advanced.
5. It is expected that this system can be realized and spread, contributing to the protection of the global environment with excellent energy prices and low CO2 emissions.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
FIG. 1 shows a structural sectional view of a conventional example of a solar cogeneration module and an enlarged view of a part (X portion) thereof. A solar cell core including the power generation cell assembly 9, the module substrate 8, the cooling medium circuit forming plate 22, and the like is fixed to the frame body 20 through the module substrate 8 with a clasp 23. The module substrate 8 is made of one flat stainless steel plate having a thickness of 0.8 mm, a cooling medium circuit forming plate 22 formed by molding a stainless steel plate having a thickness of 0.5 mm as shown in the figure, and a portion indicated by L2 in the figure. Seam welded and joined. Here, the module substrate 8 and the cooling medium circuit forming plate 22 form the cooling medium flow path 11 indicated by the width L1, and the circuit as a whole is meandering in the cooling medium over almost the entire area of the module substrate 8. It is formed so that The circuit is configured to be continuous in a meandering manner at a parallel portion having a pitch (L1 + L2) interval and U-turn portions at both ends.

    The cooling medium is water or a propylene glycol solution that is an antifreeze liquid, and flows through the cooling medium flow path 11 to receive the heat generated mainly on the surface of the power generation cell 4 to cool the power generation cell 4. In the portion L1, the cooling water directly cools the power generation cell 4 through the module substrate 8. In the portion L2, the heat generation amount of the power generation cell 4 flows through the inside of the module substrate 8 to the portion L1, where it is cooled by the cooling medium. The Therefore, L2 is set to 40 mm in the portion L2, and as a result, the heat generation amount in the power generation cell 4 in the portion L2 is transmitted to the cooling medium without a large temperature difference. The module substrate 8 and the cooling medium circuit forming plate 22 are assembled by welding, and the material is a stainless steel plate, has a very high structural strength, and the heat transfer performance of the heat generation amount of the power generation cell 4 is extremely good. Presumed.

    However, the conventional example shown in FIG. 1 has a big problem. One is long-term reliability against coolant leakage. Since the cooling medium flow path is formed by welding of stainless steel plates, there is a considerable risk of leakage due to poor welding or peeling of the weld due to long-term use. Since the actual system consisting of a large number of modules consists of a very large amount of welding work, even if the welding rate itself is very small, it can be a big problem for the system. It becomes a problem. In this sense, the cooling medium circuit system having no welded portion is the reason that is required. Second, there is a risk that peeling of the joint with the power generation cell assembly, cracking of the power generation cell 4 and disconnection of the power generation cell assembly may occur due to poor flatness of the module substrate. Module substrate welding generates large and small distortions in the module substrate, and unevenness due to welding tends to occur on the flat surface of the upper surface. In addition, the module substrate 8 and the cooling medium circuit forming plate are likely to be warped and deformed due to wind pressure or vibration external force during installation work or actual use. As a result, it is difficult to eliminate the risk that the power generation cell 4 is peeled off, cracked or disconnected. In order for the module substrate to maintain the strength and flatness as a substrate, a system in which it is an independent substrate is required.

The third problem is in terms of productivity and production equipment investment. The example shown in FIG. 1 is basically manufactured by two steps of a stainless steel plate welding step and a resin bonding step by lamination of the power generation cell assembly 9. This is a completely separate process, and providing these two separate process lines and equipment for large area and heavy modules imposes a heavy burden on the manufacturer and increases the cost of the module produced. Since one system device uses a large number of modules, an increase in manufacturing cost must be avoided unless it becomes a bottleneck in the spread of products and hinders business expansion.
As another example, a method of adhering a cooling medium circuit having a resin structure to a module flat plate has been devised. In this case, since it is made of resin and the cooling medium circuit itself is bonded to the module flat plate, it is a superior method in terms of manufacturability and quality, but the resin structure is a long-term operating environment in harsh operating environments. Reliability cannot be expected. It is difficult to avoid leakage of the cooling medium due to cracks due to material deterioration, peeling from the module substrate due to deformation, and the like. A cooling medium circuit that diverts a large number of cooling pipes from the header pipe has also been proposed, but this also impairs the reliability of the product due to the joining and welding points of the numerous pipes.

FIG. 2 is a cross-sectional view of a part of the solar cell core according to the embodiment of the present invention. The uppermost surface is covered with a cell upper surface cover 3 made of a transparent fluororesin film, thereby maintaining the bonding function of the bonding resin A6 for a long period of time and protecting the bulk silicon power generation cell assembly 9. The power generation cell assembly 9 and the module substrate 8 are softly and firmly joined to the corners by the EVA joining resins A, B, and C, and are joined without gaps. The cooling pipe 10 on the lower surface is embedded in a cooling pipe embedding portion 14 formed on the cooling pipe cover 13 and constitutes an upper flat surface 17 together with the upper surface of the cooling pipe cover 13. The upper flat surface is bonded to the lower surface of the module substrate 8 by an EVA bonding resin C12. The cooling pipe 10 has a semicircular cross-sectional shape with a diameter of 9.52 mm on the outer periphery, and the cooling pipe cover 13 has a semicircular cross-section with the cooling pipe embedded portion 14 having a diameter of the cooling pipe plus a diameter of 0.8 mm. It is molded into a shape.

The four planar members described above and the cooling pipe 10 and the cooling pipe cover 13 are joined by a lamination process in which EVA called hot-melt resin is installed between these parts and heated to 150 ° C. in a vacuum state. Be joined. Each bonding resin is a transparent EVA 0.2mm EVA sheet, B is a 0.6mm EVA sheet mixed with black paint, C is a colored 0.6mm EVA sheet, and D is the same EVA sheet as C Are used respectively. In the power generation cell assembly 9, 36 bulk silicon power generation cells 4 are arranged and connected by a power generation cell lead wire 5 to form an electric circuit so as to have a module area size. The module substrate 8 is a flat iron plate having a thickness of 0.8 mm and coated for the purpose of electrical insulation. As the cooling pipe 10, a copper pipe having a diameter of 9.52 mm and a thickness of 0.5 mm and having a D-shaped cross-sectional shape and formed in a meandering shape shown in FIG. 3 is used.

The cooling pipe cover 13 is formed by forming a cooling pipe embedded portion 14 on an aluminum flat plate having a thickness of 0.5 mm, and has a flat upper surface and is divided into nine portions by a dividing line 16 as shown in FIG. These are connected to each other with an aluminum foil tape to form a module area shape. The aluminum foil tape has a thickness of 0.05 mm and is affixed at room temperature, but a composite film tape of an adhesive layer that can withstand a lamination bonding temperature of 150 ° C. and a resin film for high temperature is used. As shown in FIG. 2, in the lamination process, the aluminum block spacer 15 is placed in the recess on the lower surface of the cooling pipe cover 13 and placed on the bed of the apparatus, and the surface pressure is applied to the cell upper surface cover 3. The joining resin melted over the entire surface is spread over the entire joining surface and joined together. Although not shown in the figure, the hooking claws of the two thin steel plates are welded to the lower surface of the module substrate 8, and the cooling pipe cover 13 is penetrated and bent to be mechanically fixed.

FIG. 3 shows the shape of the cooling pipe cover. In the aluminum cooling pipe cover, the cooling pipe embedded portion 14 is press-molded with a serpentine groove whose inner surface has a semicircular sectional shape with a diameter of the cooling pipe plus a diameter of 0.8 mm. The pitch of the meandering parallel cooling pipes is set to 70 mm. As can be seen from the enlarged view of the arrow in the Y direction, the piping and its cover are combined so that the flat surface 17 on the upper surface is flush with the entire surface, and an EVA sheet of bonding resin is fitted between the two, lamination processing Later, as shown in FIGS. FIG. 4 is a partial cross-sectional view of the solar cogeneration module and shows a state in which the solar cell core of FIG. 1 is incorporated. The module upper surface cover 1 is a tempered glass plate having a thickness of 3.2 mm, the upper heat insulating layer 2 is an air layer having a thickness of 30 mm, and the lower heat insulating layer 21 is a foamed urethane having a minimum thickness of 20 mm. Although not shown in the drawing, in order to increase the strength of the glass module upper surface cover 1, two thin columnar pillars made of fluorine rubber are incorporated in the upper heat insulating layer.

The following excellent characteristics and effects are exhibited by the above-mentioned methods, structures, and material technologies.
1. If the cooling medium flows through one pipe, the most important defect is that the medium leaks due to poor brazing, poor welding, local rust, etc. The risk of occurrence is extremely low. Therefore, as a premise of the present invention, a special structure that collects heat from a flat power generation cell was created using this single pipe. This is a high-quality, high-reliability, easy-to-manufacture, low-cost product, and therefore can provide a structure that is highly practical.
2. The solar cell core is a seven-layer laminate that is integrated as a whole, and each member is made of an average material that is thin and strong. It is possible to realize a structure that is resistant to risks such as windstorms and installation.
3. Since it is not welded, a metal module board that can maintain perfect flatness and flatness is placed in the center of this core, and a buffer layer of bonding resin is sandwiched above and below it. Since the power generation cell assembly and the cooling medium circuit body are joined, there is no adverse effect on the cell and the medium circuit body due to the joining process, and a stable joining can be obtained, so that an appropriate joining structure is easily realized.

4. The effect of 2 and 3 above and the entire surface are joined together in a vacuum, so the joint strength is extremely high, covering the periphery of the seven-layer solar cell core, and painting, etc. If the influence from is removed, peeling of the joint can be prevented.
Since the five- and seven-layer structures are joined by the three-layer joining resin EVA, it is easy to relieve the mutual thermal distortion step by step, and the operating temperature range can be expanded.
6. The heat generated in the power generation cell is transferred through the entire area of the module to the cooling medium in the cooling pipe, so it has excellent electrothermal characteristics.
7. Module board is made of iron plate, cooling pipe is one pipe, cooling pipe cover is thin aluminum plate,
Bonding resin is a hot-melt resin that is used in large quantities in the production of solar cells, and manufacturing is a one-time lamination. These basic methods are extremely effective in realizing low product costs.
8. The only major manufacturing equipment is the vacuum lamination equipment, which can minimize the capital investment and improve productivity.

  With the above effects, it is possible to produce a solar cogeneration module with high performance and long life reliability exceeding 20 years at a practical cost.

Cross-sectional view of a conventional solar cogeneration module Partial sectional view of solar cell core of the present invention and lamination spacer Cooling medium circuit body of the present invention Partial sectional view of the solar cogeneration module of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Module upper surface cover 2 Upper heat insulation layer 3 Cell upper surface cover 4 Power generation cell 5 Power generation cell lead wire 6 Resin A for joining
7 Resin B for bonding
8 Module board 9 Power generation cell assembly 10 Cooling piping 11 Cooling medium flow path 12 Resin C for bonding
13 Cooling piping cover 14 Cooling piping embedded portion 15 Aluminum block spacer 16 Dividing line 17 Upper flat surface 18 Bonding resin C
21 Lower heat insulating layer 22 Cooling medium circuit forming plate 23 Fastener

Claims (11)

In a flat-plate solar cogeneration module that receives sunlight and outputs electric power and heat on the top surface,
Solar-permeable resin or glass, flat plate or film cell top cover, solar transparent plate or film heat-responsive bonding resin A each having an approximate area shape. Assembling a flat power generation cell for outputting the electric power, a flat or film-like heat-responsive bonding resin B, a flat metal module substrate, a flat or film-like heat-responsive bonding The resin C and the flat cooling medium circuit body containing the flow path through which the cooling medium that outputs the heat communicates are stacked in multiple layers, the whole is heated in a vacuum apparatus, and the upper surface of the cell upper surface cover And a solar cell core that is integrated with each other by applying a compressive pressure from the lower surface of the cooling medium circuit body with each heat-responsive bonding resin. Down module. In a flat-plate solar cogeneration module that receives sunlight and outputs electric power and heat on the top surface,
Solar-permeable resin or glass, flat plate or film cell top cover, solar transparent plate or film heat-responsive bonding resin A each having an approximate area shape. Assembling a flat power generation cell for outputting the electric power, a flat or film-like heat-responsive bonding resin B, a flat metal module substrate, a flat or film-like heat-responsive bonding In order to output the resin C and the above-mentioned heat, one metal cooling pipe is bent and embedded in a recess formed on the upper surface of the metal cooling pipe cover to form an upper flat surface whose upper surface is substantially flat. In this way, the cooling medium circuit bodies, which are a combination of both, are stacked in multiple layers, the whole is heated in a vacuum apparatus, and the upper surface of the cell upper surface cover and the lower surface of the metal cooling pipe cover of the cooling medium circuit body Apply pressure Sunlight cogeneration Ray Deployment module, wherein incorporating the solar cell core obtained by integrating the whole is bonded by the thermal response of the adhesive resin each three layers therein. In a flat-plate solar cogeneration module that receives sunlight and outputs electric power and heat on the top surface,
Solar-permeable resin or glass, flat plate or film cell top cover, solar transparent plate or film heat-responsive bonding resin A each having an approximate area shape. Assembling a flat power generation cell for outputting the electric power, a flat or film-like heat-responsive bonding resin B, a flat metal module substrate, a flat or film-like heat-responsive bonding Resin C and a state in which a heat-responsive bonding resin D is interposed in a recess formed on the upper surface of a metal cooling pipe cover by bending a single metal cooling pipe to output the heat. The cooling medium circuit body, which is a combination of the two, is stacked in multiple layers so as to form an upper flat surface having a substantially flat upper surface, and the whole is heated in a vacuum apparatus, and the upper surface of the cell upper surface cover and the cooling Underside of the media circuit body A solar cogeneration system that incorporates a solar cell core that is integrated with a heat-responsive bonding resin disposed in three layers and in a recess of the cooling pipe by applying compression pressure. The rate module. A glass flat plate or resin flat plate with sunlight permeability is used as a module upper surface cover, an upper heat insulating layer made of an air layer below it, a flat plate solar cell core underneath, and a lower heat insulating layer successively stacked thereunder, In a solar cogeneration module in which the outer periphery of the flat plate is covered by a frame and the entire plate is formed into a flat plate shape.
A solar cogeneration module using the solar cell core according to any one of claims 1, 2, and 3 as the solar cell core. The main member of the power generation cell assembly is made of silicon or its substrate is made of a glass plate, and a flat iron plate or a surface-treated flat iron plate is used as the metal module substrate. The solar cogeneration module according to any one of 1, 2, 3, and 4. The power generation cell assembly substrate is made of aluminum, aluminum alloy, or resin, and a flat aluminum plate or a surface-treated or painted aluminum flat plate is used as the metal module substrate. Item 5. The solar cogeneration module according to any one of Items 1, 2, 3, and 4. The metal module substrate is covered with the heat-responsive bonding resins B and C so that the entire upper surface, lower surface, and end surface of the metal module substrate are covered so that the metal module substrate is not rusted or deteriorated by outside air. The solar cogeneration module according to any one of claims 1, 2, 3, 4, 5, and 6. The cooling medium circuit body is used in which a flat surface is formed on a side surface of the metal cooling pipe, and the flat surface is combined with an upper surface after forming the metal cooling pipe cover to form an upper flat surface. The solar cogeneration module according to claim 2, wherein the solar cogeneration module is provided. An iron plate or a plated iron plate is used for the module substrate and a copper pipe is used as the cooling pipe, or an aluminum plate is used for the module board and a resin pipe or an aluminum pipe whose inner surface is coated with resin is used as the cooling pipe. The solar cogeneration module according to any one of claims 2, 3, and 8. The metal cooling pipe is a semicircular shape having a flat cross section, and the flat surface is a pipe having a cross sectional shape occupying an area of 30% to 42% of the total outer surface area. The solar cogeneration module according to any one of claims 2, 3, 4, 8, and 9. In order to absorb or alleviate thermal strain generated in the cooling pipe cover made of an aluminum thin plate, at least one continuous dividing line is provided in the horizontal or vertical direction on the plane, or the thermal strain is absorbed. Forming intermittent cutting lines or bead lines that have the same effect as the dividing line, dividing the whole into a plurality of sheets, and attaching a protective tape such as an aluminum foil adhesive tape across the line, etc. The cooling pipe cover devised so as to prevent the thermal-responsive bonding resin C from leaking out, wherein any one of claims 3, 4, 5, 6, 8, 9, and 10 is used. Solar cogeneration module described in 1.

Images