Device for varying incline of photovoltaic power generation by using fluid thermal expansion

Abstract

The device for varying the incline of photovoltaic power generation inclination by using fluid thermal expansion of the present invention comprises a thermal expansion cylinder device and an automatic deviation correction device for simultaneously correcting deviations of the height and inclination angle of a photovoltaic panel. The thermal expansion cylinder device is composed of a thermal expansion fluid, a main piston, and a cylinder. The cylinder interior is filled with the thermal expansion fluid, the volume of which expands or contracts according to the temperature, thereby moving the main piston in the longitudinal direction. The linear displacement of the thermal expansion cylinder device installed between the photovoltaic panel and a fixed structure contracts when the ambient temperature is low (for example, winter solstice), thereby increasing the angle of inclination of the photovoltaic panel, and the linear displacement of the thermal expansion cylinder device expands when the temperature is high (for example, summer solstice), thereby lowering the angle of inclination of the photovoltaic panel. The automatic deviation correction device comprises an expanded volume accommodation device, a spring, an auxiliary piston, a check valve, and a pushrod. The forward movement length of the main piston is limited after summer solstice when the upper limit setting value is set. The check valve is opened by the thermal expansion fluid pressure such that the fluid flows into an excess expanded volume accommodation device. The auxiliary piston moves backward and compresses the spring, and when the temperature descends again after the highest temperature has been reached, the check valve is closed by the spring elastic force and pressure deviation.

Description

Solar power generation tilt-variable device using fluid thermal expansion

[0001] The present invention relates to a solar power generation tilt-variable device using fluid thermal expansion, which is installed between a fixed structure and a solar panel and adjusts the angle of the solar panel according to the altitude of the sun.

[0002] Korean Patent Publication No. 10-2010-0081616 discloses a solar tracking device using a thermal expansion fluid, which uses solar heat and a thermal expansion fluid whose volume expands due to solar heat as a driving source to rotate the solar collection panel in a direction that tracks the sunlight according to the direction of the sun, thereby saving energy by eliminating the need for a driving motor or the like to rotate the solar collection panel.

[0003] A solar tracking device using a thermal expansion fluid comprises a support pillar erected on the ground, a swing axis supported on the support pillar so as to be rotatable left and right, and a solar collection panel connected to the swing axis by a connecting frame so as to be rotated integrally with the swing axis around the swing axis.

[0004] It has a pair of light-receiving sections in which a thermal expansion fluid that expands in volume as the temperature rises is filled inside, and the collector plates are arranged so that the solar heat collected by each collector plate differs depending on the direction of the sun.

[0005] It has a pair of thermal expansion cylinders each having a rod that is connected to the inside of a pair of light-receiving sections and moves forward and backward according to the pressure of thermal expansion fluid flowing into the body.

[0006] It includes a power transmission means that is driven by the displacement difference between the loads of the thermal expansion cylinder and rotates the solar collector panel in a direction that tracks the sunlight according to the direction of the sun.

[0007] A solar automatic tracking device using a thermally expandable fluid that tracks the position of the sun and focuses sunlight while positioning the solar panel so that it is as perpendicular to the sun as possible is disclosed in Korean Patent Publication No. 10-1854111.

[0008] A solar automatic tracking device using a thermal expansion fluid is provided with a fluid mining tank including a first fluid mining tank and a second fluid mining tank filled with a thermal expansion fluid, which are arranged left and right on both ends of the lower part of the solar panel that receives solar heat.

[0009] It is arranged adjacent to the first fluid mining tank, and includes a first cylinder whose upper part is connected to a solar panel by a rotary joint, a body capable of containing a thermal expansion fluid therein, a sealing ring inserted into the body and raised and lowered, a spring arranged below the sealing ring and elastically deformed according to the pressure of the thermal expansion fluid, and a connecting part connected to the cylinder and the fluid mining tank.

[0010] It is a configuration that includes a fluid absorption tank that is placed between the fluid mining tank and the first cylinder and absorbs the fluid in the cylinder to adjust the pressure when the pressure inside the cylinder increases.

[0011] The first cylinder is configured to include a first cylinder body having an internal space, and a first cylinder rod inserted into the first cylinder body and moved up and down according to the pressure of a thermal expansion fluid.

[0012] The first fluid mining tank is connected to the internal space above the first cylinder rod through a hose, and the second fluid mining tank is connected to the internal space below the first cylinder rod through a hose.

[0013] The fluid absorption tank is configured to include a sealing ring that is inserted into the body and raised, a spring and cylinder that are placed under the sealing ring and elastically deformed according to the pressure of the thermally expanding fluid, and a connecting part that is connected to the fluid collection tank.

[0014] [Prior Art Literature]

[0015] [Patent Document]

[0016] (Patent Document 1) Korean Patent Publication No. KR 10-2010-0081616 A (July 15, 2010)

[0017] (Patent Document 2) Korean Patent Publication KR 10-1854111 B1 (June 14, 2018)

[0018] Currently, among the methods for increasing solar power generation, there is a problem in that the tilt angle is manually adjusted in a fixed-variable structure that changes the tilt angle according to the season, which continuously incurs labor costs, and there are often cases where the tilt angle of the solar panel cannot be changed to the appropriate angle at the appropriate time.

[0019] The purpose of the present invention is to provide a solar power tilt-variable device installed between a fixed structure and a solar panel, which automatically adjusts the angle of a solar panel for solar power generation to match the altitude of the sun by using fluid thermal expansion.

[0020] The solar power generation tilt variable device using fluid thermal expansion of the present invention includes a thermal expansion cylinder device and an automatic deviation correction device that simultaneously corrects deviations in the altitude and inclination angle of the solar panel.

[0021] The thermal expansion cylinder device of the present invention is composed of a thermal expansion fluid, a main piston, and a cylinder, and is configured such that the thermal expansion fluid is filled inside the cylinder, and the volume of the filled thermal expansion fluid expands or contracts according to the temperature (hereinafter, in the present invention, the temperature is used interchangeably as “air temperature” depending on the weather) to move the main piston in the longitudinal direction.

[0022] The linear displacement of the thermal expansion cylinder device installed between the solar panel of the present invention and the fixed structure is configured to contract when the ambient temperature (air temperature) is low, such as in the winter solstice, to increase the inclination angle of the solar panel, and the thermal expansion cylinder device is configured to expand when the air temperature is high, such as in the summer solstice, to decrease the inclination angle of the solar panel.

[0023] The automatic deviation correction device of the present invention comprises an expansion volume receiving device, a spring, an auxiliary piston, a check valve, and a push rod, and the main piston is configured such that its forward length is limited after the upper limit setting value is set.

[0024] The check valve is opened by the pressure of the thermal expansion fluid of the present invention, allowing the fluid to flow into the over-expansion volume receiving device, the auxiliary piston retracts to compress the spring, and when the maximum temperature is reached and the device descends again, the check valve is closed by the spring elasticity and pressure deviation.

[0025] In the present invention, even when the temperature continues to drop in the fall and winter, the check valve (10) remains closed, and the stroke length is reduced as the main piston retreats due to the contraction of the thermal expansion fluid.

[0026] As the temperature of the present invention decreases, the main piston continues to retreat, and when the check valve push rod is forcibly retreated near the minimum point, which is the lower limit setting value, the check valve opens again, and the high-pressure thermal expansion fluid in the over-expansion volume receiving device flows into the main cylinder, and this continues until the minimum temperature, and when the temperature rises again, the main piston advances and the check valve remains closed.

[0027] In the present invention, the check valve is closed in the spring, which is the temperature rising section, the check valve is opened in the summer, which is the temperature range from the upper limit to the highest temperature, the check valve is closed in the fall, which is the temperature falling section, and the check valve is opened in the winter, which is the temperature range from the lower limit to the lowest temperature.

[0028] In the present invention, the solar altitude that changes according to the season corresponds to the linear displacement of the following thermal expansion cylinder device and the inclination angle of the solar panel in the following (Formula 1) and (Formula 2) relationships, and the length of the thermal expansion cylinder device is automatically adjusted to compensate for the deviation of the solar altitude and temperature. The length adjustment of the thermal expansion cylinder device is configured to correct the expansion length of the thermal expansion cylinder device to a positive (+) value in the temperature rising section from the winter solstice to the summer solstice, thereby increasing the length of the device, and to correct it to a negative (-) value in the temperature decreasing section from the summer solstice to the winter solstice, thereby decreasing the length of the device.

[0029] (Formula 1) Temperature-cylinder linear displacement relationship

[0030]

[0031] : cylinder displacement, : coefficient of fluid thermal expansion, : Volume at reference temperature (0℃), : temperature

[0032] (Formula 2) Temperature-solar panel inclination relationship

[0033]

[0034] : Panel inclination angle, : Device length at reference temperature (0℃)

[0035] In the present invention, since solar energy is the greatest when sunlight is vertically incident on the panel, in order to match the vertical incidence angle of the solar panel according to the solar altitude and the temperature at that time, the expansion length of the thermal expansion cylinder device is adjusted so that the inclination angle of the solar panel is corrected according to the following (Formula 3), and the maximum and minimum lengths are limited in summer (June to August) and winter (December to February), respectively, and the length of the thermal expansion cylinder device is automatically adjusted according to the relationship between the solar altitude and the temperature, thereby varying the inclination angle of the solar panel.

[0036] (Formula 3) Corrected solar panel tilt angle relationship

[0037]

[0038] Here, γ is a correction value (design variable) that is positive (+) when the temperature rises and negative (-) when the temperature falls.

[0039] In the present invention, in order to reduce the weight of the driving part of the thermal expansion cylinder of the solar power generation tilt variable device, the thermal expansion fluid storage unit and the cylinder are separated, and the thermal expansion fluid storage unit and the cylinder are configured as a separate structure connected by a tube.

[0040] In the present invention, when it is necessary to distribute the load or when a long array is installed in the horizontal direction, when a multi-type thermal expansion fluid storage unit is installed with multiple cylinders through a manifold (34), the cylinder displacement and the inclination angle of the solar panel when each piston receives the same load are characterized by changing in response to the related equations of the following (Equation 4) and (Equation 5).

[0041] (Formula 4) Multi-type displacement relationship

[0042] ( : Number of cylinders)

[0043] (Formula 5) Multi-type slope relationship

[0044]

[0045] In the present invention, when the piston stroke length must be long, the principle of amplification using the area ratio, which is the difference in the cross-sectional areas of the main piston and the auxiliary piston, is applied, and the displacement and inclination angle in the case where there is no thermal expansion of the hydraulic oil of the amplification section are characterized in that they change in response to the related relations of the following (Formula 6) and (Formula 7).

[0046] (Formula 6) Displacement relationship of the amplified type

[0047]

[0048] (Formula 7) Slope relationship of the amplified type

[0049]

[0050] The automatic deviation correction device of the present invention comprises a piston shaft, an adjusting device, a spring, a damper, a latch, a push rod, and a guide.

[0051] In the spring and fall, which are the temperature rising periods of the present invention, the main piston continues to advance due to the expansion of the thermal expansion fluid as the temperature rises, and when it reaches the upper limit set value, the longitudinal displacement is limited by the guide.

[0052] As the temperature of the present invention continues to rise, the main piston advances to compress the spring and the piston shaft is locked by a latch. In the fall and winter when the temperature drops, the spring is compressed, the piston shaft remains locked, and the main piston retreats due to the contraction of the thermal expansion fluid.

[0053] When the temperature of the present invention continues to drop and reaches the lower limit set point, the push rod is pushed to release the latch, the spring and adjusting device are inflated again, and a damper is provided to cushion the shock when the latch is released.

[0054] In the spring, which is the temperature rising section of the present invention, the main piston advances, and when the temperature reaches the upper limit setting point, it enters a locked state limited by a latch, and in the fall, which is the temperature decreasing section, the spring is compressed, the piston shaft maintains the locked state, and the main piston retracts due to the contraction of the expanding fluid.

[0055] In the present invention, when the temperature continues to drop and reaches the lowest temperature range, which is winter, from the lower limit set value, the push rod is pushed, the latch is released, and the spring and adjusting device are configured to return to the expanded state.

[0056] The present invention is easy to maintain because it operates automatically according to temperature without a separate driving force, and because it continuously changes according to temperature and responds to daily solar altitude changes according to the daily temperature range, it can increase power generation compared to existing fixed variable types.

[0057] In addition, it is expected to have a significant effect of more than 5% in power generation compared to a fixed structure with a variable slope, and since the principle and structure are simple, it is easy to manufacture and can be developed in various ways, and optimization is possible because the slope angle according to temperature can be quantitatively calculated.

[0058] In addition, it has the advantage of being able to operate with a large range of inclination adjustment, which is advantageous for snow loads in winter with a high inclination angle, and for wind loads (typhoons) in summer with a low inclination angle. In particular, in the case of a structure with an automatic compensation function, the temperature lag characteristic compared to the solar altitude can be supplemented, thereby further increasing power generation.

[0059] Figures 1(a) and (b) are a schematic and a schematic diagram, respectively, of a thermal expansion cylinder used in a solar power generation tilt-variable device using fluid thermal expansion.

[0060] Figures 2(a) and (b) are installation drawings showing the application of a thermal expansion cylinder device of a solar power generation tilt variable device between a solar panel and a fixed structure, and installation drawings showing the state in which the tilt angle of the solar power generation tilt variable device changes according to temperature, respectively.

[0061] Figures 3(a) and (b) are drawings explaining the relationship between temperature and piston displacement in a thermal expansion cylinder device of a solar power generation tilt-variable device, and the relationship between temperature and the inclination angle of a solar panel in a thermal expansion cylinder device of a solar power generation tilt-variable device, respectively.

[0062] Figure 4 is a graph showing the relationship between solar altitude and the vertical incidence angle of the solar panel.

[0063] Figure 5 is a predicted graph of solar altitude tracking of a thermal expansion cylinder including a correction function for correcting solar altitude and temperature deviation of Figure 4.

[0064] Figures 6(a), (b), (c), and (d) illustrate a solar power generation tilt variable device using fluid thermal expansion having a hydraulic type deviation automatic compensation device according to temperature rise and temperature drop.

[0065] Figures 7(a), (b), (c), and (d) illustrate a solar power generation tilt variable device using fluid thermal expansion having a mechanical type deviation automatic compensation device according to temperature rise and temperature drop.

[0066] Figures 8(a) and (b) are a conceptual diagram and a manufacturing example diagram of a separate structure in which the thermal expansion fluid storage unit and the cylinder are separated to reduce the weight of the driving unit of the thermal expansion cylinder of a solar power generation tilt variable device, respectively.

[0067] Figures 9(a) and (b) illustrate a multi-type structure employed when distributing the load of the driving part of a thermal expansion cylinder, and an amplified structure employed when the piston stroke length must be long, respectively.

[0068] Figure 10 is a test photograph confirming the slope change performance as the temperature changes from low to high.

[0069] Among the methods for increasing solar power generation, a fixed-variable structure that changes the inclination angle according to the season is being used.

[0070] Since the inclination angle is adjusted manually, labor costs are continuously incurred, and there is a problem that the panel inclination angle is often not changed to the appropriate angle at the appropriate time due to lack of expertise on the part of the workers.

[0071] Accordingly, the present invention proposes a solar power generation tilt-variable device that is installed between a fixed structure and a solar panel by using fluid thermal expansion, and in which the angle of the solar panel is automatically adjusted according to the solar altitude.

[0072] Hereinafter, with reference to the attached drawings, a solar power generation tilt variable device using fluid thermal expansion according to the present invention will be described in more detail.

[0073] Figures 1(a) and (b) are a schematic and a schematic diagram, respectively, of a thermal expansion cylinder used in a solar power generation tilt-variable device using fluid thermal expansion.

[0074] A thermal expansion cylinder device of a solar power generation tilt variable device using fluid thermal expansion is configured to include a thermal expansion fluid (1), a main piston (2), and a cylinder (3).

[0075] A thermal expansion fluid (1) is filled inside the cylinder (3), and the volume of the filled thermal expansion fluid (1) expands or contracts depending on the temperature (hereinafter, in the present invention, the temperature is used interchangeably as “air temperature” depending on the weather), thereby moving the main piston (2) in the longitudinal direction.

[0076] Figures 2(a) and (b) are installation drawings showing the application of a thermal expansion cylinder device of a solar power generation tilt variable device between a solar panel and a fixed structure, and installation drawings showing the state in which the tilt angle of the solar power generation tilt variable device changes according to temperature, respectively.

[0077] The thermal expansion cylinder device (4) is installed between the solar panel (5) and the fixed structure (6), and is configured to correspond to the solar altitude that changes with the seasons by contracting when the ambient temperature is low, such as in the winter solstice, to increase the inclination angle of the panel, and expanding when the temperature is high, such as in the summer solstice, to decrease the inclination angle.

[0078] Figures 3(a) and (b) are drawings explaining the relationship between temperature and piston displacement in a thermal expansion cylinder device of a solar power generation tilt-variable device, and the relationship between temperature and the inclination angle of a solar panel in a thermal expansion cylinder device of a solar power generation tilt-variable device, respectively.

[0079] The relationship between the linear displacement of the cylinder and temperature in a thermal expansion cylinder device is as follows.

[0080] (Formula 1) Temperature-cylinder linear displacement relationship

[0081]

[0082] : cylinder displacement, : coefficient of fluid thermal expansion, : Volume at reference temperature (0℃), : temperature

[0083] The relationship between the inclination angle of the solar panel and temperature in a variable structure with a thermal expansion cylinder device installed is as follows.

[0084] (Formula 2) Temperature-solar panel inclination relationship

[0085]

[0086] : Panel inclination angle, : Device length at reference temperature (0℃)

[0087] In order to optimize the inclination angle of the thermal expansion cylinder device according to (Formula 1) and (Formula 2), the following method is adopted.

[0088] Solar energy is greatest when sunlight is incident perpendicularly on the panel, so the vertical incidence angle (=θ) on the panel must match the solar altitude and the temperature at that time.

[0089] Since the solar altitude at a specific time at a specific location can be obtained through calculations or astronomical data, the temperature is predicted using past weather data or data from the Korea Meteorological Administration.

[0090] The slope angle according to the expected temperature is calculated using (Formula 1).

[0091] The response characteristics are optimized by adjusting the thermal expansion coefficient of the fluid (β), fluid filling volume (V0), piston diameter (d), and structure installation location (a, b, c0).

[0092] The vertical incidence angle behavior of solar panels based on the monthly average temperature at noon in Busan in 2022 was estimated using the temperature-solar panel inclination angle relationship equation, as shown in [Table 1] below.

[0093] Monthly average temperature, device length, panel vertical incidence angle, solar altitude, panel inclination angle, January 4.04, 12.25, 37.22, 34.20, 52.78, February 3.44, 11.99, 36.13, 43.31, 53.87, March 10.40, 15.00, 48.53, 54.21, 41.47, April 14.95, 16.98, 56.66, 6.03, 3.34, May 18.98, 18.72, 64.01, 74.28, 25.99, June 21.59, 19.85, 68 .8779.9921.13Jul26.0721.7977.5273.8512.48Aug26.5922.0278.5666.1211.44Sep22.8920.4271.3555.2618.65Oct17.7818.2061.8044.0428.2011Nov14.6116.8356.0535.8033.95Dec3.2411.9035.7931.0854.21

[0094] Figure 4 is a graph showing the relationship between solar altitude and the vertical incidence angle of the solar panel.

[0095] Looking at the tracking characteristics of the solar altitude based on the monthly average temperature at noon in Busan in 2022, the black line represents the solar altitude, the red line represents the vertical angle of the solar panel, and the dotted line represents the inclination angle of the thermal expansion cylinder device.

[0096] Figure 5 is a predicted graph of solar altitude tracking of a thermal expansion cylinder including a correction function for correcting solar altitude and temperature deviation of Figure 4.

[0097] The sun's altitude is at its lowest point (around June 21), but the temperature continues to rise due to energy accumulation, reaching its highest temperature in July and August.

[0098] Therefore, a structure that simply expands according to temperature has the characteristic of following the sun's altitude slightly behind, as shown in Fig. 5.

[0099] The solar tracking performance of a solar panel can be improved by automatically adjusting the length of the thermal expansion cylinder device (c in Fig. 3(b)) to compensate for deviations in solar altitude and temperature.

[0100] The length adjustment of the thermal expansion cylinder device is performed by correcting the expansion length of the thermal expansion cylinder device to a positive (+) value in the temperature rising section from the winter solstice to the summer solstice, thereby increasing the length of the device, and by correcting it to a negative (-) value in the temperature decreasing section from the summer solstice to the winter solstice, thereby decreasing the length of the device.

[0101] The relationship for correcting the inclination angle by adjusting the expansion length of the thermal expansion cylinder device is as follows.

[0102] (Formula 3) Corrected solar panel tilt angle relationship

[0103]

[0104] γ is a correction value (design variable) that is positive (+) when the temperature rises and negative (-) when the temperature falls.

[0105] In sections Ⅰ and Ⅲ, which are spring (March to June) and fall (September to December) of Fig. 5, the slope relationship can be corrected as in (Formula 3), and in sections Ⅱ and Ⅳ, which are summer (June to August) and winter (December to February), the maximum and minimum lengths are each limited and are affected by the temperature exceeding the set value.

[0106] By automatically adjusting the length of the thermal expansion cylinder device according to the solar altitude and temperature relationship and by automatically varying the tilt angle of the solar power generation panel, the amount of solar power generation can be increased.

[0107] A hydraulic or mechanical type automatic deviation correction device having a function of automatically correcting the deviation of a thermal expansion cylinder device of a solar power generation tilt variable device can be provided.

[0108] Figures 6(a), (b), (c), and (d) illustrate a solar power generation tilt variable device using fluid thermal expansion having a hydraulic type deviation automatic compensation device according to temperature rise and temperature drop.

[0109] The hydraulic deviation automatic compensation device is equipped with an expansion volume receiving device (7), a spring (8), an auxiliary piston (9), a check valve (10), and a push rod (11).

[0110] As the temperature rises in spring and summer, which are seasons with rising temperatures, the main piston (2) moves forward due to thermal expansion of the fluid (1).

[0111] After the upper limit setting value, the forward length of the main piston (2) is mechanically limited, and when the temperature rises beyond that, the check valve (10) is opened by the expansion pressure of the thermal expansion fluid (1), and the thermal expansion fluid (1) flows into the over-expansion volume receiving device (7).

[0112] The auxiliary piston (9) retracts to compress the spring (8), and when it descends again after reaching the maximum temperature, the check valve (10) closes due to the spring elasticity and pressure deviation.

[0113] Even when the temperature continues to drop in the fall and winter when the temperature drops, the check valve (10) remains closed, and the main piston (2) retracts due to the contraction of the thermal expansion fluid (1), reducing the stroke length.

[0114] As the temperature decreases, the main piston (2) continues to retreat and forcibly retreats the check valve push rod (11) near the minimum point (lower limit setting value), which is the same as the check valve (10) opens again and the high-pressure thermal expansion fluid in the over-expansion volume receiving device (7) flows into the main cylinder (2), which continues until the lowest temperature.

[0115] Afterwards, when the temperature rises again, the main piston (2) moves forward and the check valve (10) remains closed.

[0116] The spring (8) can be changed to a cylinder structure with gas enclosed within it.

[0117] In the spring (Ⅰ), which is the section where the temperature rises, the check valve (10) is closed (Fig. 6(a)).

[0118] In summer (Ⅱ), when the temperature is in the highest temperature range (lower limit), the check valve (10) is opened (Fig. 6(b)).

[0119] In the fall (Ⅲ), when the temperature is falling, the check valve (10) is closed (Fig. 6(c)).

[0120] In winter (Ⅳ), when the temperature is in the lowest temperature range (winter solstice), the check valve (10) is opened (Fig. 6(d)).

[0121] Figures 7(a), (b), (c), and (d) illustrate a solar power generation tilt variable device using fluid thermal expansion having a mechanical type deviation automatic compensation device according to temperature rise and temperature drop.

[0122] The mechanical deviation automatic compensation device is equipped with a piston shaft (17), an adjusting device (20), a spring (21), a damper (22), a latch (23), a push rod (24), and a guide (25).

[0123] In the spring and fall (sections Ⅰ and Ⅱ), which are periods of rising temperature, the main piston (2) continues to advance due to the expansion of the thermal expansion fluid (1) as the temperature rises, and when it reaches the upper limit set value (lower limit), the longitudinal displacement is limited by the guide (25).

[0124] As the temperature continues to rise, the main piston (2) moves forward, compressing the spring (21) and the piston shaft (17) is locked by the latch (23).

[0125] In the fall and winter (III, IV sections) when the temperature drops, the spring (21) is compressed, the piston shaft (17) is kept in a locked state, and the main piston (2) is retracted due to the contraction of the thermal expansion fluid (1).

[0126] When the temperature continues to drop and reaches the lower limit setting value (winter solstice), the push rod (24) is pushed, the latch (23) is released, and the spring (21) and the adjusting device (20) are in an expanded state again.

[0127] A damper (22) is provided to absorb shock when the latch (23) is released.

[0128] In the spring (Ⅰ), which is the section where the temperature rises, the main piston (2) moves forward (Fig. 7(a)).

[0129] When the temperature reaches the upper limit setting point (not the upper limit setting point), it enters a locked state limited by the latch (23) (Fig. 6(b)).

[0130] In the fall (Ⅲ), which is a section where the temperature decreases, the spring (21) is compressed, the piston shaft (17) is kept in a locked state, and the main piston (2) is retracted by the contraction of the expansion fluid (1) (Fig. 7(c)).

[0131] When the temperature continues to drop and reaches the lowest temperature range (winter) from the lower limit setting value (winter solstice), the push rod (24) is pushed, the latch (23) is released, and the spring (21) and the adjusting device (20) are in an expanded state again (Fig. 7(d)).

[0132] Figures 8(a) and (b) are a conceptual diagram and a manufacturing example diagram of a separate structure in which the thermal expansion fluid storage unit and the cylinder are separated to reduce the weight of the driving unit of the thermal expansion cylinder of a solar power generation tilt variable device, respectively.

[0133] In order to reduce the weight of the driving part of the thermal expansion cylinder, a configuration in which the thermal expansion fluid storage unit (33) and the cylinder (31) are separated and the thermal expansion fluid storage unit (33) and the cylinder (31) are connected by a tube (32) can be applied. At this time, the relationship equations (Formula 1) and (Formula 2) as in the basic form can be applied.

[0134] Figures 9(a) and (b) illustrate a multi-type structure employed when distributing the load of the driving part of a thermal expansion cylinder, and an amplified structure employed when the piston stroke length must be long, respectively.

[0135] In cases where it is necessary to distribute the load or a long array is installed in the horizontal direction, a multi-type system in which multiple thermal expansion fluid storage units (33) are installed through a manifold (34) can be applied.

[0136] The relationship between displacement and tilt angle when each piston receives the same load is as follows.

[0137] (Formula 4) Multi-type displacement relationship

[0138] ( : Number of cylinders)

[0139] (Formula 5) Multi-type slope relationship

[0140]

[0141] When the piston stroke length must be long, when a fluid with a relatively small coefficient of thermal expansion is used, or when miniaturization is required, a structure capable of amplifying displacement can be applied.

[0142] The principle of amplification using the area ratio, which is the difference in the cross-sectional areas of the main piston (36) and the auxiliary piston (35), is applied, and the relationship between displacement and inclination angle in the case where there is no thermal expansion of the hydraulic oil (37) of the amplification section is as follows.

[0143] (Formula 6) Displacement relationship of the amplified type

[0144]

[0145] (Formula 7) Slope relationship of the amplified type

[0146]

[0147] Figure 10 is a test photograph confirming the slope change performance as the temperature changes from low to high.

[0148] This photo shows the slope change performance as it goes from low temperature on the left to high temperature on the right.

[0149] As described above, the present invention has the following advantages.

[0150] It is easy to maintain as it operates automatically according to temperature without a separate driving force.

[0151] It continuously changes according to temperature and responds to daily solar altitude changes according to the daily temperature range, so it can increase power generation compared to existing fixed variable types.

[0152] As a variable-slope structure, it is expected to have a significant effect of more than 5% in power generation compared to a fixed structure.

[0153] Because the principle and structure are simple, it is easy to manufacture and can be developed in various ways. Since the inclination angle according to temperature can be quantitatively calculated, optimization is possible.

[0154] For structures with an automatic compensation function, power generation can be further increased by compensating for the temperature lag characteristic relative to solar altitude.

[0155] The range of inclination adjustment can be widened, so it can be operated with a high inclination angle in winter to be advantageous for snow loads, and with a low inclination angle in summer to be advantageous for wind loads (typhoons).

[0156] Although the present invention has been described in detail through representative examples above, those skilled in the art to which the present invention pertains will understand that various modifications can be made to the above-described embodiments without departing from the scope of the present invention.

[0157] Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by all changes or modifications derived from the claims and equivalent concepts as well as the claims described below.

[0158] [Explanation of symbols]

[0159] 1: Thermally expanding fluid

[0160] 2: Main piston

[0161] 3: Cylinder

[0162] 4: Thermal expansion cylinder device

[0163] 5: Solar panels

[0164] 6: Fixed structures

[0165] 7: Expansion volume receiving device

[0166] 8: Spring

[0167] 9: Auxiliary piston

[0168] 10: Check valve

[0169] 11: Push rod

[0170] 17: Piston shaft

[0171] 20: Adjustment device

[0172] 21: Spring

[0173] 22: Damper

[0174] 23: Latch

[0175] 24: Pushrod

[0176] 25: Guide

[0177] 31: Cylinder

[0178] 32: Tube

[0179] 33: Thermal expansion fluid storage unit

[0180] 34: Manifold

[0181] 35: Auxiliary piston

[0182] 36: Main piston

Claims

1. The solar power generation tilt variable device using fluid thermal expansion includes a thermal expansion cylinder device and an automatic deviation correction device that simultaneously corrects the deviation in the height and inclination angle of the solar panel. The thermal expansion cylinder device (4) is composed of a thermal expansion fluid (1), a main piston (2), and a cylinder (3). A thermal expansion fluid (1) is filled inside the cylinder (3), and the volume of the filled thermal expansion fluid (1) expands or contracts depending on the temperature, thereby moving the main piston (2) in the longitudinal direction. The linear displacement of the thermal expansion cylinder device (4) installed between the solar panel (5) and the fixed structure (6) contracts when the ambient temperature is low, such as in winter, and increases the inclination angle of the solar panel. When the temperature is high, such as at the lower body, the thermal expansion cylinder device (4) expands in linear displacement to lower the inclination angle of the solar panel. The automatic deviation compensation device is equipped with an expansion volume receiving device (7), a spring (8), an auxiliary piston (9), a check valve (10), and a push rod (11). The main piston is limited in its forward length after the upper limit setting value is set, the check valve (10) is opened by the pressure of the thermal expansion fluid (1), and the fluid flows into the over-expansion volume receiving device (7), and the auxiliary piston (9) retracts to compress the spring (8). A solar power generation slope variable device using fluid thermal expansion, characterized in that when the temperature reaches the highest point and then decreases again, the check valve (10) is closed by the elasticity of the spring (8) and pressure deviation.

2. In paragraph 1, Even when the temperature continues to drop in the fall and winter when the temperature drops, the check valve (10) remains closed, and the main piston (2) retracts due to the contraction of the thermal expansion fluid (1), reducing the stroke length. As the temperature decreases, the main piston (2) continues to retreat and forcibly retreats the check valve push rod (11) near the minimum point, which is the lower limit setting value, so that the check valve (10) opens again and the high-pressure thermal expansion fluid in the over-expansion volume receiving device (7) flows into the main cylinder (2), which continues until the lowest temperature. A solar power generation tilt variable device using fluid thermal expansion, characterized in that when the temperature rises again, the main piston (2) moves forward and the check valve (10) remains closed.

3. In paragraph 1, In the spring, when the temperature rises, the check valve (10) closes, and in the summer, when the temperature is at its highest temperature, the check valve (10) opens. A solar power generation slope variable device using fluid thermal expansion, characterized in that the check valve (10) is closed in the fall, when the temperature is falling, and the check valve (10) is opened in the winter, when the temperature is at its lowest temperature.

4. In any one of paragraphs 1 to 3, The solar altitude, which changes with the seasons, corresponds to the linear displacement of the thermal expansion cylinder device and the inclination angle of the solar panel according to the following relationships (Formula 1) and (Formula 2). Adjustment of the length of the thermal expansion cylinder device to have the function of automatically adjusting the length of the thermal expansion cylinder device to compensate for the deviation of solar altitude and temperature, In the temperature rise section from the winter solstice to the summer solstice, the expansion length of the thermal expansion cylinder device is corrected to a positive (+) value, so that the length of the device increases. A solar power generation tilt variable device using fluid thermal expansion characterized in that the length of the device is reduced by compensating for a negative (-) value in the temperature decreasing section from the summer solstice to the winter solstice. (Formula 1) Temperature-cylinder linear displacement relationship : Cylinder displacement, : coefficient of fluid thermal expansion, : Volume at reference temperature (0℃), : temperature (Formula 2) Temperature-solar panel inclination relationship : Panel inclination angle, : Device length at reference temperature (0℃) 5. In any one of paragraphs 1 to 3, Since solar energy is the largest when sunlight is incident vertically on the panel, in order to match the vertical incidence angle of the solar panel according to the solar altitude and the temperature at that time, the expansion length of the thermal expansion cylinder device is adjusted so that the inclination angle of the solar panel is corrected according to the following (Formula 3). A solar power generation tilt-variable device using fluid thermal expansion, characterized in that the maximum and minimum lengths are limited in summer (June to August) and winter (December to February), respectively, and the length of the thermal expansion cylinder device is automatically adjusted according to the relationship between solar altitude and temperature, thereby varying the tilt angle of the solar panel. (Formula 3) Corrected solar panel tilt angle relationship Here, γ is a correction value (design variable) that is positive (+) when the temperature rises and negative (-) when the temperature falls.

6. In any one of paragraphs 1 to 3, A solar power generation tilt-variable device using fluid thermal expansion, characterized in that the driving part of the thermal expansion cylinder (3) of the solar power generation tilt-variable device is configured as a separate structure in which the thermal expansion fluid storage part (33) and the cylinder (31) are separated and the thermal expansion fluid storage part (33) and the cylinder (31) are connected by a tube (32).

7. In any one of paragraphs 1 to 3, In cases where it is necessary to distribute the load or a long array is installed in the horizontal direction, a multi-type in which multiple thermal expansion fluid storage units (33) are installed through a manifold (34) is applied, and the cylinder displacement and the inclination angle of the solar panel when each piston receives the same load are characterized by changing in response to the related relations of (Formula 4) and (Formula 5) below. A solar power generation tilt variable device using fluid thermal expansion. (Formula 4) Multi-type displacement relationship ( : Number of cylinders) (Formula 5) Multi-type slope relationship 8. In any one of paragraphs 1 to 3, In cases where the piston stroke length must be long, the principle of amplification using the area ratio, which is the difference in the cross-sectional areas of the main piston (36) and the auxiliary piston (35), is applied, and the displacement and inclination angle in the case where there is no thermal expansion of the hydraulic oil (37) of the amplifying section are changed in response to the related relations of the following (Formula 6) and (Formula 7). A solar power generation tilt variable device using fluid thermal expansion. (Formula 6) Displacement relationship of the amplified type (Formula 7) Slope relationship of the amplified type 9. The solar power generation tilt variable device using fluid thermal expansion includes a thermal expansion cylinder device and an automatic deviation correction device that simultaneously corrects the deviation in the height and inclination angle of the solar panel. The thermal expansion cylinder device (4) is composed of a thermal expansion fluid (1), a main piston (2), and a cylinder (3). A thermal expansion fluid (1) is filled inside the cylinder (3), and the volume of the filled thermal expansion fluid (1) expands or contracts depending on the temperature, thereby moving the main piston (2) in the longitudinal direction. The linear displacement of the thermal expansion cylinder device (4) installed between the solar panel (5) and the fixed structure (6) contracts when the ambient temperature is low, such as in winter, and increases the inclination angle of the solar panel. When the temperature is high, such as at the lower body, the thermal expansion cylinder device (4) expands in linear displacement to lower the inclination angle of the solar panel. The automatic deviation compensation device comprises a piston shaft (17), an adjustment device (20), a spring (21), a damper (22), a latch (23), a push rod (24), and a guide (25). In the spring and fall, which are periods of rising temperature, the main piston (2) continues to advance due to the expansion of the thermal expansion fluid (1) as the temperature rises, and when it reaches the upper limit set value, the longitudinal displacement is limited by the guide (25). As the temperature continues to rise, the main piston (2) moves forward, compressing the spring (21) and the piston shaft (17) is locked by the latch (23). In the fall and winter when the temperature drops, the spring (21) is compressed, the piston shaft (17) is kept locked, and the main piston (2) is retracted by the contraction of the thermal expansion fluid (1). When the temperature continues to drop and reaches the lower limit setting value, the push rod (24) is pushed, the latch (23) is released, and the spring (21) and the adjusting device (20) are in an expanded state again. A solar power generation tilt variable device using fluid thermal expansion, characterized in that it is equipped with a damper (22) for shock absorption when a latch (23) is released.

10. In paragraph 9, In the spring, when the temperature rises, the main piston (2) moves forward, and when the temperature reaches the upper limit setting point, it is locked by the latch (23). In the fall, when the temperature is dropping, the spring (21) is compressed, the piston shaft (17) is kept locked, and the main piston (2) is retracted by the contraction of the expansion fluid (1). A solar power generation tilt variable device using fluid thermal expansion, characterized in that when the temperature reaches the lowest temperature range in winter, which is the lowest set value, due to a continuous decrease in temperature, the push rod (24) is pushed, the latch (23) is released, and the spring (21) and the adjusting device (20) return to an expanded state.

11. In paragraph 9 or 10, The solar altitude, which changes with the seasons, corresponds to the linear displacement of the thermal expansion cylinder device and the inclination angle of the solar panel according to the following relationships (Formula 1) and (Formula 2). Adjustment of the length of the thermal expansion cylinder device to have the function of automatically adjusting the length of the thermal expansion cylinder device to compensate for the deviation of solar altitude and temperature, In the temperature rise section from the winter solstice to the summer solstice, the expansion length of the thermal expansion cylinder device is corrected to a positive (+) value, so that the length of the device increases. A solar power generation tilt variable device using fluid thermal expansion, characterized in that the length of the device is reduced by compensating for a negative (-) value in the temperature decreasing section from the summer solstice to the winter solstice. (Formula 1) Temperature-cylinder linear displacement relationship : Cylinder displacement, : coefficient of fluid thermal expansion, : Volume at reference temperature (0℃), : temperature (Formula 2) Temperature-solar panel inclination relationship : Panel inclination angle, : Device length at reference temperature (0℃) 12. In paragraph 9 or paragraph 10, Since solar energy is the largest when sunlight is incident vertically on the panel, in order to match the vertical incidence angle of the solar panel according to the solar altitude and the temperature at that time, the expansion length of the thermal expansion cylinder device is adjusted so that the inclination angle of the solar panel is corrected according to the following (Formula 3). A solar power generation tilt-variable device using fluid thermal expansion, characterized in that the maximum and minimum lengths are limited in summer (June to August) and winter (December to February), respectively, and the length of the thermal expansion cylinder device is automatically adjusted according to the relationship between solar altitude and temperature, thereby varying the tilt angle of the solar panel. (Formula 3) Corrected solar panel tilt angle relationship Here, γ is a correction value (design variable) that is positive (+) when the temperature rises and negative (-) when the temperature falls.

13. In paragraph 9 or 10, A solar power generation tilt-variable device using fluid thermal expansion, characterized in that the driving part of the thermal expansion cylinder (3) of the solar power generation tilt-variable device is configured as a separate structure in which the thermal expansion fluid storage part (33) and the cylinder (31) are separated and the thermal expansion fluid storage part (33) and the cylinder (31) are connected by a tube (32).

14. In paragraph 9 or 10, In cases where it is necessary to distribute the load or a long array is installed in the horizontal direction, a multi-type in which multiple thermal expansion fluid storage units (33) are installed through a manifold (34) is applied, and the cylinder displacement and the inclination angle of the solar panel when each piston receives the same load are characterized by changing in response to the related relations of (Formula 4) and (Formula 5) below. A solar power generation tilt variable device using fluid thermal expansion. (Formula 4) Multi-type displacement relationship ( : Number of cylinders) (Formula 5) Multi-type slope relationship 15. In paragraph 9 or paragraph 10, In cases where the piston stroke length must be long, the principle of amplification using the area ratio, which is the difference in the cross-sectional areas of the main piston (36) and the auxiliary piston (35), is applied, and the displacement and inclination angle in the case where there is no thermal expansion of the hydraulic oil (37) of the amplifying section are changed in response to the related relations of the following (Formula 6) and (Formula 7). A solar power generation tilt variable device using fluid thermal expansion. (Formula 6) Displacement relationship of the amplified type (Formula 7) Slope relationship of the amplified type

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