JP4981589B2 - Solar power generation / heat collection combined use device - Google Patents

Description

  The present invention relates to a combined solar power generation / heat collection device including a solar battery.

For the purpose of preventing global warming, effective use of natural energy has been studied in order to suppress carbon dioxide emissions, and solar water heaters and solar cells have already been commercialized.
Of these solar cells, the crystalline silicon type is known to have a reduced power generation efficiency because the band gap becomes smaller as the temperature rises. For this reason, as described in Patent Documents 1 and 2 below, the power generation / heat collection composite module in which the solar cell is thermally connected to the heat collection surface of the solar heat collector is separated from the module. In a solar hot water supply apparatus having a hot water storage tank provided in a solar cell, a heat medium such as an antifreeze liquid that exchanges heat with water to be supplied with hot water or water to be supplied with hot water is circulated to the back side of the solar cell. A battery is cooled to suppress a decrease in power generation efficiency.
At this time, there are two circulation paths as paths for circulating water or the like for cooling the solar cell. One is a path (hereinafter referred to as a heat collection path) for circulating water or the like between the solar heat collector and the hot water storage tank. The other is a path for circulating water or the like (hereinafter referred to as a heat dissipation path) between the solar heat collector and the atmospheric heat radiator (radiator).
Switching between these two paths is performed as follows. First, the operation of the hot water supply apparatus is started by circulating the heat medium through the heat collection path. Monitor the temperature of water at the outlet of the solar heat collector and the temperature of water in the hot water storage tank, and when the difference between the two drops below the specified value, or the temperature of the water in the hot water storage tank rises above the specified value When this happens, the circulation path is switched from the heat collection path to the heat dissipation path.
Japanese Patent Laid-Open No. 56-168059 JP-A-11-37570

As described above, the conventional solar power generation / heat collection combined use device is configured such that when the difference between the temperature of the water at the outlet of the solar heat collector and the temperature of the water at the hot water storage tank falls below a predetermined value, the water etc. The circulation path is switched from the heat collection path to the heat dissipation path. However, in such switching control of the circulation path, the operation in the heat collection path is performed until the temperature in the hot water storage tank becomes considerably high, and it becomes impossible to cool the solar cell effectively. There is a problem that the decrease in efficiency cannot be effectively suppressed.
The present invention has been made in view of the above problems, and solar power generation capable of maximizing power generation efficiency in a system using a power generation / heat collection composite module in which a solar cell and a solar heat collector are integrated.・ The purpose is to provide a combined heat collection device.

In order to solve the above-described problems, the solar power generation / heat collection combined utilization device of the present invention is
A solar collector that collects solar heat and heats the heat medium;
A solar cell provided thermally connected to the surface of the solar heat collector;
A heat medium storage tank for storing the heat medium;
A heat collecting conduit for circulating a heat medium between the solar heat collector and the heat medium storage tank;
An atmospheric radiator that radiates heat from the heat medium heated by the solar heat collector to the atmosphere;
A heat radiating conduit for circulating a heat medium between the solar heat collector and the atmospheric heat radiator;
Solar cell output detecting means for detecting the output of the solar cell;
Solar cell temperature detecting means for detecting the temperature of the solar cell;
A heat medium temperature detecting means for detecting the temperature of the heat medium in the heat medium storage tank;
Atmospheric temperature detection means for detecting the temperature of the atmosphere;
Based on the detection value of the solar cell output detection means, the detection value of the solar cell temperature detection means, and the detection value of the heat medium temperature detection means, the heat medium is expected to circulate through the heat collecting pipe. A heat collection power generation increase calculating means for calculating the power generation increase of the solar cell;
The amount of power required to circulate the heat medium through the heat collecting pipe is subtracted from the amount of increase in power generation calculated by the power generation increase amount calculation means at the time of heat collection, and the difference is calculated as the power increase at the time of heat collection. Means for calculating the actual increased power generation amount during heat collection;
Based on the detection value of the solar cell output detection means, the detection value of the solar cell temperature detection means, and the detection value of the atmospheric temperature detection means, the heat medium is expected to circulate through the heat radiating conduit. A heat dissipation power generation increase calculation means for calculating the increase in power generation of the solar cell,
Subtracting the amount of power required to circulate the heat medium through the heat radiating pipe from the amount of increase in power generation calculated by the power generation increase during heat dissipation calculation means, and calculating the difference as the power increase during heat dissipation Means for calculating the actual increase in power generation time,
Compare the calculated actual power generation amount at the time of heat collection with the actual increase power generation amount at the time of heat dissipation, and determine which circulation path of the heat collection pipe line or the heat radiation pipe line to circulate the heat medium. Pipeline selection means to
Switching means for switching the circulation path of the heat medium between the heat collecting pipe and the heat radiating pipe according to the selection result of the pipe selection means.

  In the solar power generation / heat collection combined utilization apparatus of the present invention, heat exchange is performed between the compressor that compresses the refrigerant to high temperature and high pressure, and the compressed refrigerant and the heat medium from the heat medium storage tank. A heat exchanger for performing the heat exchange, expansion means for expanding and depressurizing the refrigerant subjected to the heat exchange, an evaporator for performing heat exchange between the expanded refrigerant and the atmosphere, and evaporating the refrigerant, and the evaporation A heat pump device provided between the compressor and the compressor, and having a sub-heat exchanger that raises the refrigerant temperature by exchanging heat between the heat medium from the heat medium storage tank and the evaporated heat medium It is preferable to provide.

Moreover, in the solar power generation / heat collection combined utilization apparatus of the present invention, the temperature stratification of the heat medium is formed inside the heat medium storage tank, and the heat medium temperature detecting means is in the low temperature layer of the temperature stratification. While detecting the temperature of the heat medium as the heat medium temperature,
When the detected heat medium temperature is higher than a desired temperature, the heat medium is taken out from the intermediate temperature layer of the temperature stratification and used for use,
When the detected heat medium temperature is lower than a desired temperature, it is preferable to take out the heat medium from the high temperature layer of the temperature stratification and use it.

  According to the present invention, either the circulation path for circulating the heat medium between the solar heat collector and the heat medium storage tank, or the circulation path for circulating the heat medium between the solar heat collector and the atmospheric radiator. It is determined whether the power generation efficiency of the solar cell is further improved if the heat medium is circulated, and the heat medium is circulated through one of the paths according to the determination result. Therefore, the power generation efficiency in the system using the power generation / heat collection composite module in which the solar cell and the solar heat collector are integrated can be maximized.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, detailed descriptions of known means that have been widely employed are omitted.
(Embodiment 1)

FIG. 1 shows a schematic configuration of a solar system 1 to which a combined photovoltaic power generation / heat collection device according to an embodiment of the present invention is applied.
The solar system 1 includes a power generation / heat collection composite module 4 including a solar heat collector 2 and a solar cell 3 provided in thermal connection with the heat collection surface 2a, and a hot water supply heated by the solar heat collector 2. A hot water storage tank (heat medium storage tank) 5 for storing water as a heat medium, and an atmospheric radiator 6 for radiating heat into the atmosphere from the water deprived of the solar cell 3 by the solar heat collector 2; As a main component.
Here, the solar heat collector 2 and the hot water storage tank 5 are connected by a heat collecting pipe 7, and water is circulated between the solar heat collector 2 and the hot water storage tank 5 through the heat collecting pipe 7. Further, the solar heat collector 2 and the atmospheric heat radiator 6 are connected by a heat radiation pipe 8, and water is circulated between the solar heat collector 2 and the atmospheric heat radiator 6 through the heat radiation pipe 8.
Further, the solar system 1 selects which of the heat collection pipe line 7 and the heat radiation pipe line 8 is to circulate water, and performs a process such as switching the circulation path according to the selection result, and a hot water supply A second controller 51 for controlling the operation of the solar system 1 at the time, and a temperature controller 52 for setting a hot water supply temperature in the solar system 1. In addition, the solar system 1 includes a solar cell output detection unit D1 that detects the output (electromotive force) of the solar cell 3, a solar cell temperature detection unit D2 that detects the temperature of the solar cell 3, and water in the hot water storage tank 5. The heat medium temperature detecting means D3 for detecting the temperature of the air, the air temperature detecting means D4 provided around the air radiator 6 for detecting the air temperature, and the first control unit 9 for selecting / switching the circulation path. A data storage unit D5 that stores various types of information to be referred to when processing is performed.

Here, the solar heat collector 2 is, for example, a flat plate heat collector in which water is heated by solar heat, and has a heat collecting surface 2a that directly contacts water and heats the water. ing. Further, a solar cell 3 is provided so as to be thermally connected to the heat collecting surface 2a, and the solar heat received by the solar cell 3 is transmitted to the heat collecting surface 2a.
The solar cell 3 has a light receiving surface 3a that receives sunlight, and generates electricity according to the amount of received light. In the present embodiment, for example, a polycrystalline silicon type solar cell is used as the solar cell 3. Polycrystalline silicon solar cells have a good balance between cost and performance, but have a small energy gap and a relatively large decrease in power generation due to temperature rise. Therefore, the water circulation path is switched so that a larger amount of heat is radiated from the solar cell 3 to the water via the heat collecting surface 2a of the solar heat collector 2 and the solar cell 3 is cooled more effectively. Thus, the power generation efficiency of the solar cell 3 can be greatly improved.

The hot water storage tank 5 is provided with an upper water outlet 21, an intermediate water outlet 22 and a lower water outlet 23 at the upper part, middle part and lower part, respectively, and so-called temperature stratification is formed therein. That is, in the hot water storage tank 5, the temperature of water increases from the lower part toward the upper part. Here, the temperature of the lower part of the hot water storage tank 5 (the temperature near the lower water outlet 23) T2 (refer to Equation 2 below) is constantly measured by the heat medium temperature detecting means D3 as the heat medium temperature, and the measured value is Input to the first control unit 9.
A water replenishing port 67 for replenishing water via a water pipe 61 when the amount of water decreases due to hot water supply or the like is provided at the lower part of the hot water storage tank 5.

  The atmospheric radiator 6 is sent from the solar heat collector 2 through a different path from the hot water storage tank 5 so that the solar battery 3 can be effectively cooled by water and the decrease in power generation capacity can be suppressed. The heat of coming water is released into the atmosphere.

The heat collection pipe 7 is a pipe for circulating water between the solar heat collector 2 and the hot water storage tank 5, and is a first pipe that connects the water outlet 32 of the solar heat collector 2 and the first three-way valve 33. A pipe 34, a second pipe 35 that connects the first three-way valve 33 and the intermediate water inlet / outlet port 22 of the hot water tank 5, a third pipe 37 that connects the lower water outlet 23 of the hot water tank 5 and the second three-way valve 36, It consists of a fourth pipe 39 connecting the second three-way valve 36 and the first pump 38 and a fifth pipe 41 connecting the first pump 38 and the water inlet 40 of the solar heat collector 2. In the heat collecting pipe 7, water is circulated by the first pump 38.
Here, the circulation of the water through the heat collecting pipe 7 takes water heated by the solar heat collector 2 into the hot water storage tank 5 from the intermediate water inlet / outlet port 22 of the hot water storage tank 5, while the lower water outlet 23 of the hot water storage tank 5. The relatively low temperature water is taken out from the hot water storage tank 5 and returned to the solar heat collector 2. Thereby, the temperature in the hot water storage tank 5 is effectively raised.

  The heat radiation pipe 8 is a pipe for circulating water between the solar heat collector 2 and the atmospheric heat radiator 6, and connects the first pipe 34, the first three-way valve 33 and the atmospheric heat radiator 6 described above. The sixth pipe 42, the seventh pipe 43 connecting the atmospheric radiator 6 and the second three-way valve 36, the fourth pipe 39, and the fifth pipe 41. In the heat radiating pipe 8, water is also circulated by the first pump 38.

  The first control unit 9 selects the circulation path when water is circulated through either the heat collection pipe line 7 or the heat radiation pipe line 8, and performs the circulation according to the selection result of the first pump 38. Operation control and switching control of the first three-way valve 33 and the second three-way valve 36 are performed. The specific processing contents of this control will be described in detail later.

  The solar system 1 also includes a heat pump device 10 for heating the water by absorbing the latent heat in the atmosphere when the temperature of the hot water supplied does not reach the desired temperature. The heat pump device 10 compresses the refrigerant to a high temperature and a high pressure, the radiator 12 that releases the heat of the refrigerant that has reached a high temperature to the water sent from the hot water storage tank 5, and the water after heating Expansion means 13 for expanding and reducing the pressure of the refrigerant, an evaporator 14 for heating and evaporating the refrigerant that has been reduced in temperature by the atmosphere, and the refrigerant evaporated in the evaporator 14 by water from the hot water storage tank 5 The auxiliary heat exchanger 15 for heating and a refrigerant circulation line 16 as a refrigerant passage which is a closed pipe line connecting these parts are provided.

Here, the auxiliary heat exchanger 15 passes through a sixth pipe 37 connecting the lower water outlet 23 of the hot water storage tank 5 and the second three-way valve 36, and a seventh pipe 64 branched in the middle of the sixth pipe 37. Water from the low temperature layer of the hot water storage tank 5 is supplied. The water that has undergone heat exchange in the auxiliary heat exchanger 15 and has been lowered in temperature is returned to the hot water storage tank 5 side through the eighth pipe 65. The eighth pipe 65 is a pipe branched from the sixth pipe 37 at a position closer to the hot water storage tank 5 than a branch position with the seventh pipe 64. Further, a ninth pipe 71 for feeding water from the middle of the eighth pipe 65 to the radiator 12 of the heat pump apparatus 10 is branched. The water whose temperature has been lowered in the auxiliary heat exchanger 15 is mixed with the water directly sent from the lower water outlet 23 of the hot water storage tank 5 and sent to the radiator 12 through the ninth pipe 71. Here, a second pump 56 is provided in the middle of the ninth pipe 71, and water is circulated between the hot water storage tank 5, the radiator 12 and the auxiliary heat exchanger 15 by the output of the second pump 56. Is called.
Further, the eighth pipe 65 is provided with a throttle valve 55, and the amount of water circulation to the auxiliary heat exchanger 15 is adjusted by the opening degree of the throttle valve 55.

  The water heated by the refrigerant in the radiator 12 and heated to a high temperature is returned to the water return port 66 provided in the upper part of the hot water storage tank 5 through the tenth pipe 68. Here, in the operation control of the second pump 56 and the compressor 11, the second control unit 51 compares the hot water supply set temperature by the temperature controller 52 with the detected temperature of the heat medium temperature detecting means D <b> 3 to detect the heat medium temperature. The second pump 56 and the compressor 11 are activated when the detected temperature of the means D3 is lower than the hot water supply set temperature by a predetermined temperature or more.

  As described above, the refrigerant pressure from the evaporator 14 is increased by heating the refrigerant with the water taken out from the lower water outlet 23 of the hot water storage tank 5 in the auxiliary heat exchanger 15 of the heat pump device 10. Thus, the difference from the refrigerant pressure on the radiator 12 side can be reduced. Thereby, it becomes possible to reduce the electric input amount to the compressor 11, and to improve the COP (coefficient of performance) of the heat pump apparatus 10.

Below, operation | movement of the solar system 1 of the said structure is demonstrated.
First, the operation of the daytime solar system 1 with solar radiation will be described with reference to the flowchart of FIG. In FIG. 2, reference numerals S1, S2,... Represent step numbers.
First, the output (electromotive force) P1 of the solar cell 3 is detected by the solar cell output detection means D1, and the detected value is input to the first controller 9 (S1), and the solar cell 3 is detected by the solar cell temperature detection means D2. The temperature T1 is detected, and the detected value is similarly input to the first controller 9 (S2).
Next, the temperature T2 below the hot water storage tank 5 is detected by the heat medium temperature detecting means D3, and the detected value is input to the first control unit 9 as the heat medium temperature (the water temperature of the low temperature layer of the temperature stratification) (S3). , Predetermined information (specifically, Δt, F1, ρ1, Cp1, α1 below) that is referred to when calculating the actual power generation amount ΔW1 during heat collection based on the input detection values P1, T1, and T2. And R1) are input from the data storage unit D5 to the first control unit 9 (S4).

Here, the actual power generation amount ΔW1 at the time of heat collection means that the temperature of the water in the solar heat collector 2 is lowered by circulating water through the heat collection pipe 7, and the cooling efficiency of the solar cell 3 is increased. This is an increase in the amount of power generation of the solar cell 3 that is expected to increase substantially. That is, the actual power generation amount ΔW1 at the time of heat collection is an increase amount of the power generation amount of the solar cell 3 after elapse of a predetermined time Δt expected by circulating water through the heat collection pipe line 7 as shown in the following formula (1). The amount of power consumed by the first pump 38 required to circulate water through the heat collection pipe 7 from ΔP1 (referred to as an estimated power generation increase amount) and the electric input Wp1 of the first pump 38 when water is circulated through the heat collection pipe 7 This is a value obtained by subtracting the product (= Wp1 × Δt) with the predetermined time Δt.
ΔW1 = ΔP1−Wp1 × Δt (1)
A more specific method for calculating the estimated power generation increase ΔP1 is as follows. That is, the following formulas 2 and 3 are combined to calculate the estimated temperature T4 of the solar cell 3 and the estimated temperature T5 of the water at the water outlet 32 of the solar heat collector 2 after a predetermined time Δt has elapsed.
(T4−T1) / Δt = α1 × {(T4 + T1) / 2− (T5 + T2) / 2} × R1 (2)
F1 * [rho] 1 * Cp1 * (T5-T2) = [alpha] 1 * {(T4 + T1) / 2- (T5 + T2) / 2} * R1 (3)
Where F1: heat medium (water) flow rate, ρ1: heat medium (water) density, Cp1: specific heat, α1: heat transfer coefficient of the solar heat collector 2, R1: heat collecting surface 2a of the solar heat collector 2 Area (heat transfer area).

Next, the calculated estimated temperature T4 of the solar cell 3 and the estimated temperature T5 of water are substituted into the following equation 4 to calculate the estimated power generation increase ΔP1 of the solar cell 3 after a predetermined time Δt has elapsed.
ΔP1 = P1 × {f (T4) −f (T1)} × Δt (4)
However, the function f is a function regarding the temperature dependence of the power generation amount of the solar cell 3 as shown in FIG. 3, and the data storage unit D5 uses the output when the temperature of the solar cell 3 is 25 degrees Celsius as a reference. The relative output of the solar cell 3 (100%) is stored as table data with the battery temperature as a variable. That is, f (T4) indicates the relative output of the solar cell 3 corresponding to the estimated temperature T4 of the solar cell 3 after the predetermined time Δt has elapsed, and f (T1) corresponds to the current temperature T1 of the solar cell 3. The relative output of the solar cell 3 is shown.

  Next, the atmospheric temperature T3 detected by the atmospheric temperature detection means D4 in step S6 is input to the first controller 9, and input in the detection values P1 and T1 input in the steps S1 and S2 and in step S6. Predetermined information to be referred to when calculating the actual heat generation amount ΔW2 at the time of heat release based on the detected value T3 (specifically, Δt, F1, ρ1, Cp1, α1 and R2 below) Is input from the data storage unit D5 to the first control unit 9 (S7).

Here, the substantially increased power generation amount ΔW2 at the time of heat dissipation is expected to increase substantially due to a decrease in the temperature of the water in the solar heat collector 2 by circulating water through the heat dissipation pipe 8. This is an increase in the amount of power generated by the solar cell 3. That is, the actual increase in power generation amount ΔW2 at the time of heat dissipation is the increase in power generation amount of the solar cell 3 after the elapse of a predetermined time Δt expected by circulating water through the heat radiation pipe 8 (estimated power generation) The amount of power consumed by the first pump 38 required to circulate water through the heat radiating pipe 8 from ΔP2 (increase amount) (the electric input Wp2 of the first pump 38 when water is circulated through the heat radiating pipe 8 and the predetermined time) This is a value obtained by subtracting the product of Δt (calculated as Wp2 × Δt).
ΔW2 = ΔP2−Wp2 × Δt (5)
A more specific calculation method of the estimated power generation increase amount ΔP2 is as follows. That is, the following formulas 6, 7, and 8 are combined, and the estimated temperature T14 of the solar cell 3 after the lapse of the predetermined time Δt, the estimated temperature T15 of the water at the water outlet 32 of the solar heat collector 2, and the solar heat collector 2 An estimated temperature T16 of water at the water inlet 40 is calculated.
(T14−T1) / Δt = α1 × {(T14 + T1) / 2− (T16 + T15) / 2} × R1 (6)
F2 × ρ1 × Cp1 × (T15−T16) = α1 × {(T14 + T1) / 2− (T15 + T16) / 2} × R1 (7)
F2 * [rho] 1 * Cp1 * (T16-T15) = [alpha] 2 * {T3- (T15 + T16) / 2} * R2 (8)
Here, R2 is the area (heat transfer area) of the heat collecting surface 2a of the solar heat collector 2.
Next, the calculated estimated temperatures T14, T15, and T16 are substituted into the following equation 9 to calculate the estimated power generation increase ΔP2 of the solar cell 3 after a predetermined time Δt has elapsed.
ΔP2 = P1 × {f (T14) −f (T1)} × Δt (9)
Here, as described above, f (T14) represents the relative output corresponding to the estimated temperature T14 of the solar cell 3 after the lapse of the predetermined time Δt, and f (T1) corresponds to the current temperature T1 of the solar cell 3. Indicates relative output.

  Next, in step S9, it is determined whether any one of the heat collection actual increase power generation amount ΔW1 calculated in step S5 and the heat dissipation substantial increase power generation amount ΔW2 calculated in step S8 is zero or more. To do. Here, if both the ΔW1 value and the ΔW2 value are negative, no substantial increase in power generation can be expected even if water is circulated through any of the heat collecting pipe 7 and the heat radiating pipe 8. The process returns to step S1 assuming that no circulation is performed. On the other hand, if either the ΔW1 value or the ΔW2 value is zero or more, the process proceeds to the next step S10.

  In step S10, the ΔW2 value is subtracted from the ΔW1 value, and in the next step S11, it is determined whether or not the difference (ΔW1−ΔW2) is greater than or equal to zero. If the above difference (ΔW1−ΔW2) is greater than or equal to zero, the heat collection pipe 7 is selected as a larger increase in power generation can be expected when water is circulated through the heat collection pipe 7. Is switched so that the first three-way valve 33 and the second three-way valve 36 are circulated (S12), and the process is terminated. On the other hand, if the difference (ΔW 1 −ΔW 2) is negative, the heat radiating pipe 8 is selected as a result that water can be circulated through the heat radiating pipe 8 and a larger increase in power generation can be expected. Switching control of the first three-way valve 33 and the second three-way valve 36 is performed so as to circulate water (S13), and the process is terminated.

  The first control unit 9 repeatedly executes the steps S1 to S13 at intervals of the predetermined time Δt. As a result, the water circulation path can be switched between the heat collection pipe line 7 and the heat radiation pipe line 8 at a timely time, so that the substantial increase in the power generation amount of the solar cell 3 can always be controlled to the maximum. It becomes.

Next, the operation at the time of hot water supply of the solar system 1 will be described.
At the time of hot water supply, the second control unit 51 subtracts the temperature (T2) of the water detected by the heat medium temperature detecting means D3 from the set temperature (desired temperature) Ts of the hot water set by the temperature controller 52, The difference (Ts−T2) is calculated. When the difference (Ts−T2) is positive, that is, when the detected value of the water temperature does not reach the set temperature, the second control unit 51 takes out water from the upper water outlet 21 having a relatively high temperature in the hot water storage tank 5. And control to use. That is, the third three-way valve 54 is switched so that the water from the upper water outlet 21 flows toward the hot water tap 53 through the eleventh pipe 63 and the hot water supply pipe 72 that connect the upper water outlet 21 and the third three-way valve 54. Water from the upper water outlet 21 is mixed with water from a water pipe (not shown) and the temperature is adjusted, and then hot water is supplied from the hot water tap 53.
On the other hand, when the difference (Ts−T2) is less than zero, that is, when the detected value of the water temperature is higher than the set temperature, water is taken out from the intermediate water inlet / outlet 22 having a temperature lower than that of the upper water outlet 21 and used. Control as follows. That is, the third three-way valve 54 is switched so that water from the intermediate water inlet / outlet port 22 flows toward the hot water tap 53 through the twelfth pipe 62 and the hot water supply pipe 72 branched from the second pipe 35. The water from the intermediate water inlet / outlet 22 is mixed with water from a water pipe (not shown) and the temperature is adjusted, and then hot water is supplied from the hot water tap 53.

By controlling as described above at the time of hot water supply, when the temperature of the water in the hot water storage tank 5 is sufficiently high, the water is taken out from the intermediate temperature layer instead of the high temperature layer in the temperature stratification and used for temperature adjustment. Therefore, the amount of tap water or the like to be mixed can be reduced, and the amount of heat stored in the water can be used more efficiently.
Thus, in the solar system 1 of the present embodiment, the temperature of the water stored in the hot water storage tank 5 is suppressed to a relatively low temperature in order to more effectively suppress the decrease in power generation efficiency due to the temperature increase of the solar cell 3. It is supposed to be. For this reason, the intermediate layer temperature of the hot water storage tank 5 often does not reach the temperature set by the temperature controller 52, and the opportunity to perform the hot water storage operation by operating the heat pump device 10 also increases. Therefore, since the water in the hot water storage tank 5 is often used as a refrigerant heating source in the auxiliary heat exchanger 15 of the heat pump device 10, the above-described effect of improving the COP (coefficient of performance) is also compared with the conventional device. It becomes possible to make it more prominent.

(Example)
Hereinafter, with reference to FIGS. 4-8, the result of the simulation which verified how much the electric power generation efficiency in the solar system 1 of this embodiment improves from a conventional apparatus is demonstrated. FIG. 4 is a configuration diagram of an example of a solar power generation / heat collection combined utilization device as a conventional device that is a comparison target of power generation efficiency improvement, FIG. 5 is a flowchart showing the operation of this conventional device, and FIG. FIG. 7 is a graph showing the correlation between the change in the amount of solar radiation and the change in the amount of solar cell power generation, which is one of the weather conditions that are the basis of the above, and FIG. 7 is the degree of improvement in the power generation efficiency of the solar system 1 of the present embodiment by the above simulation. FIG. 8 is a graph showing the degree of improvement in power generation efficiency of the conventional apparatus and the transition of the stored heat medium temperature according to the simulation.
In FIG. 6, the transition of the amount of solar radiation in summer and in fine weather is shown as an example. In this example, the amount of solar radiation is based on the reference (100%) when the temperature of the solar cell 3 is 25 degrees Celsius. It is shown that the output of the solar cell 3 is reduced to about 73% if there is no cooling around 12:00 which is the maximum.

  As shown in FIG. 4, the conventional apparatus 100 as a comparison target in the simulation includes a solar heat collector 101, a solar cell 102, a heat collector heat medium temperature detecting means 103, a hot water storage tank 104, and a hot water tank heat medium temperature detecting means. 105, an air radiator 106, a heat collecting pipe 107, and a heat radiating pipe 108. The conventional device 100 does not have an element corresponding to the heat pump device 10 of the solar system 1.

  As shown in FIG. 5, in the conventional apparatus 100, the heat collector temperature detection means 103 detects the heat medium temperature T21 at the outlet of the solar heat collector 101 (S21), and the hot water storage tank heat medium temperature detection means 105 is detected. Thus, the temperature T22 of the water in the hot water storage tank 104 is detected (S22). The temperature T22 is subtracted from the temperature T21 to calculate the difference (T21-T22) (S23), and it is determined whether the calculated difference (T21-T22) is larger than the set temperature difference ΔT (S24). If the difference (T21-T22) is larger than the set temperature difference ΔT, water is circulated through the heat collecting pipe 106 (S25), whereas if the difference (T21-T22) is less than the set temperature difference ΔT, the heat radiation pipe Water is circulated through 107 (S26).

Table 1 below shows specifications of the conventional device 100 and the solar system 1 of the present embodiment in the simulation of the present example.

As shown in FIG. 7, in the solar system 1 of the present embodiment, water is circulated through the heat radiation pipe 8 from 7 o'clock to 12 o'clock. As a result, the temperature of the water inside the solar heat collector 2 is kept low, and the amount of power generation per square meter of the solar cell 3 that increases substantially compared with the case where water circulation is not performed (substantial increase) The amount of power generation (unit: Wh / m ² · day) increases consistently with the increase in solar radiation. During this time, since the water in the hot water storage tank 5 is not circulated, the temperature is kept low (about 25 degrees Celsius).
And if the circulation path of water switches to the heat collection pipe line 7 before 12:00 when the amount of solar radiation becomes the maximum, the solar cell 3 will be cooled by the water in the hot water storage tank 5 hold | maintained at the low temperature until that time. For this reason, the substantially increased power generation amount at 12:00 in the solar system 1 jumps up to nearly 30 (Wh / m ² · day). At this time, the temperature of the water in the hot water storage tank 5 rises to about 45 degrees Celsius until the circulation path is switched again to the heat radiation pipe 8 before 13:00.
If the water circulation path is switched from the heat collecting pipe 7 to the heat radiating pipe 8 before 13:00, the temperature rise of the water in the hot water storage tank 5 stops and is maintained at about 45 degrees Celsius. On the other hand, the substantially increased power generation amount decreases from 13:00 with the same transition as in the conventional apparatus 10 described below.

On the other hand, as shown in FIG. 8, in the conventional apparatus 100, water is circulated through the heat collecting pipe 107 from 7:00 to 13:00. Meanwhile, the temperature of the heat medium in the hot water storage tank 104 rises consistently, reaching about 60 degrees Celsius at 12:00 and about 65 degrees Celsius at 13:00. At this time, the substantially increased power generation amount (unit: Wh / m ² · day) changes in the range of 2 to 11. In particular, after 9 o'clock, the water for cooling the solar cell 102 becomes relatively high temperature, so that the substantially increased power generation amount does not increase so much despite the increase in solar radiation amount (see Fig. 6), and the solar radiation amount is maximum. It remains at 11 (Wh / m ² · day) even at 12:00.
When the water circulation path is switched from the heat collecting pipe 107 to the heat radiating pipe 108 between 12:00 and 13:00, the temperature of the water that cools the solar battery 102 is lowered, and thereby the substantially increased power generation amount of the solar battery is 20 ( Wh / m ² · day) jumps to near (13:00). After that, the actual increased power generation amount decreases consistently until 18:00 as the amount of solar radiation decreases. During this time, since the water in the hot water storage tank 104 is kept without being circulated, the temperature is maintained at about 65 degrees Celsius.

  Thus, in the conventional apparatus 100, the temperature of the water for cooling the solar cell 102 is already about 60 degrees Celsius in the time zone around 12:00 when the amount of solar radiation is large and the maximum power generation amount can be obtained. The solar cell 102 cannot be effectively cooled in such a time zone. For this reason, in the conventional apparatus 100, power generation efficiency cannot be improved effectively. On the other hand, in the solar system 1 of the present embodiment, until the time zone around 12:00, water is circulated through the heat radiating pipe 8 to cool the solar cell 3 while increasing the amount of generated power. In the time zone around 12:00 when the amount is maximum, the solar cell 3 is cooled using the water in the hot water storage tank 5 kept at a low temperature until that time.

For this reason, in the solar system 1 of this embodiment, it is possible to achieve a significantly higher power generation efficiency improvement than the conventional device, especially in the time zone around 12:00 where the amount of solar radiation is large. As for the integrated value of the daily increase of the power generation efficiency, the conventional apparatus 100, 94Wh / m ² next whereas in the solar system 1 integrated value thereof is 114Wh / m ^2, than the conventional apparatus 100 to about The result that it was possible to raise the improvement degree of 21% power generation efficiency was obtained.

On the other hand, the heat output (heat energy stored in the water), to the integrated value of the day that is 231Wh / m ² in the solar system 1, the conventional apparatus 100, 469Wh / m ^2, and the above power generation efficiency The total energy efficiency obtained by adding the degree of improvement and the heat output is lower in the solar system 1. However, considering the balance between electric power and heat demand in the home, the heat output by the conventional device 100 is excessive, and it is possible to sufficiently meet the heat demand in the home with the heat output of the solar system 1 of this embodiment. . Therefore, it can be said that the solar system 1 of the present embodiment having higher efficiency with respect to the power generation output with higher exergy is more suitable for use at home.

As mentioned above, although this invention was demonstrated by embodiment and an Example, this invention is not restricted to this, A various change is possible.
For example, in the embodiment, the heat medium to be used (for example, water) is directly circulated between the solar heat collector 2 and the hot water storage tank 5 or the atmospheric radiator 6. The present invention can also be applied to the case where a heat medium (for example, antifreeze) for heat exchange is circulated between the solar heat collector 2 and the hot water storage tank 5 or the atmospheric radiator 6.

  The solar power generation and heat collecting apparatus according to the present invention can be developed as a high-efficiency power generation system using solar energy from a home power generation system to a regional distributed power generation system.

It is a block diagram of the solar power generation / heat collection combined utilization apparatus which concerns on one Embodiment of this invention. It is a flowchart which shows the process of selection / switching of the thermal-medium circulation path | route in the said embodiment apparatus. It is a graph showing the temperature dependence of the solar cell output of the said embodiment apparatus. It is a block diagram of the solar power generation / heat collection combined utilization apparatus in a prior art example. It is a flowchart which shows operation | movement of the said conventional apparatus. It is a graph which shows the correlation with the solar radiation conditions at the time of summer and fine weather, and the relative output change of a solar cell. It is a graph which shows the simulation result regarding the improvement degree of electric power generation efficiency in the said embodiment apparatus, and a heat medium temperature. It is a graph which shows the simulation result regarding the improvement degree of the power generation efficiency in the said conventional apparatus, and a heat medium temperature.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solar system 2 Solar heat collector 3 Solar cell 5 Hot water storage tank 6 Atmospheric radiator 7 Heat collection pipe 8 Heat radiation pipe 9 1st control part 10 Heat pump apparatus 11 Compressor 12 Radiator 13 Expansion means 14 Evaporator 15 Sub heat exchange Unit 33 First three-way valve 36 Second three-way valve 51 Second controller 52 Temperature controller 54 Third three-way valve D1 Solar cell output detection means D2 Solar cell temperature detection means D3 Heat medium temperature detection means D4 Atmospheric temperature detection means

Claims (3)

A solar collector that collects solar heat and heats the heat medium;
A solar cell provided thermally connected to the surface of the solar heat collector;
A heat medium storage tank for storing the heat medium;
A heat collecting conduit for circulating a heat medium between the solar heat collector and the heat medium storage tank;
An atmospheric radiator that radiates heat from the heat medium heated by the solar heat collector to the atmosphere;
A heat radiating conduit for circulating a heat medium between the solar heat collector and the atmospheric heat radiator;
Solar cell output detecting means for detecting the output of the solar cell;
Solar cell temperature detecting means for detecting the temperature of the solar cell;
A heat medium temperature detecting means for detecting the temperature of the heat medium in the heat medium storage tank;
Atmospheric temperature detection means for detecting the temperature of the atmosphere;
Based on the detection value of the solar cell output detection means, the detection value of the solar cell temperature detection means, and the detection value of the heat medium temperature detection means, the heat medium is expected to circulate through the heat collecting pipe. A heat collection power generation increase calculating means for calculating the power generation increase of the solar cell;
The amount of power required to circulate the heat medium through the heat collecting pipe is subtracted from the amount of increase in power generation calculated by the power generation increase amount calculation means at the time of heat collection, and the difference is calculated as the power increase at the time of heat collection. Means for calculating the actual increased power generation amount during heat collection;
Based on the detection value of the solar cell output detection means, the detection value of the solar cell temperature detection means, and the detection value of the atmospheric temperature detection means, the heat medium is expected to circulate through the heat radiating conduit. A heat dissipation power generation increase calculation means for calculating the increase in power generation of the solar cell,
Subtracting the amount of power required to circulate the heat medium through the heat radiating pipe from the amount of increase in power generation calculated by the power generation increase during heat dissipation calculation means, and calculating the difference as the power increase during heat dissipation Means for calculating the actual increase in power generation time,
Compare the calculated actual power generation amount at the time of heat collection with the actual increase power generation amount at the time of heat dissipation, and determine which circulation path of the heat collection pipe line or the heat radiation pipe line to circulate the heat medium. Pipeline selection means to
Switching means for switching the circulation path of the heat medium between the heat collecting pipe and the heat radiating pipe according to the selection result of the pipe selection means;
A solar power generation / heat collection combined utilization device characterized by comprising:   A compressor that compresses the refrigerant to a high temperature and a high pressure, a heat exchanger that exchanges heat between the compressed refrigerant and the heat medium from the heat medium storage tank, and the refrigerant that has undergone the heat exchange Expansion means for expanding and reducing pressure, an evaporator for exchanging heat between the expanded refrigerant and the atmosphere to evaporate the refrigerant, and the heat medium storage provided between the evaporator and the compressor The solar light according to claim 1, further comprising a heat pump device having a sub heat exchanger that performs heat exchange between the heat medium from the tank and the evaporated heat medium to raise a refrigerant temperature. Combined power generation and heat collection equipment. A temperature stratification of the heat medium is formed inside the heat medium storage tank, and the heat medium temperature detecting means detects the temperature of the heat medium in the low temperature layer of the temperature stratification as the heat medium temperature,
When the detected heat medium temperature is higher than a desired temperature, the heat medium is taken out from the intermediate temperature layer of the temperature stratification and used for use,
3. The photovoltaic power generation and heat collection according to claim 1 or 2, wherein when the detected heat medium temperature is lower than a desired temperature, the heat medium is taken out from the high temperature layer of the temperature stratification and used. Multi-use device.

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