JP6538516B2 - Solar heat collecting system and cooling medium supply system - Google Patents

Description

  Embodiments of the present invention relate to a solar heat collection system and a cooling medium supply system.

  A solar heat collection system which collects solar heat from solar rays is generally classified into a trough type, a Fresnel type, a tower type, a fixed panel type and the like. 14 and 15 show a trough type solar heat collecting system. FIG. 16 shows the heat collector 1 that constitutes a trough-type solar heat collection system. In FIG. 14 to FIG. 16, the same or similar components are denoted by the same reference numerals, and repeated description of each component is omitted.

  FIG. 16 is a perspective view showing the structure of a conventional heat collector 1.

  The heat collector 1 of FIG. 16 includes a plurality of reflecting mirrors 2 and a plurality of heat collecting tubes 3. Specifically, FIG. 16 shows two rows of reflecting mirrors 2 and two heat collecting tubes 3, and each row of reflecting mirrors 2 includes three reflecting mirrors 2. The heat collecting pipes 3 are connected in parallel to the heat medium flow path 4. The heat collector 1 heats the heat medium in the heat collection tube 3 by condensing the sunlight S on the heat collection tube 3 by the reflecting mirror 2. The heat medium is, for example, water or oil.

  Each reflecting mirror 2 has a curved surface shape whose longitudinal direction is the horizontal direction. The cross-sectional shape perpendicular to the longitudinal direction of each reflecting mirror 2 is a parabola. The heat collector 1 rotationally drives the reflecting mirror 2 so that the sun ray S is parallel to the axis of the parabola (the straight line connecting the focal point and the apex). That is, the reflecting mirror 2 tracks the sun with respect to the altitude. The center of rotation of the reflecting mirror 2 may or may not coincide with the focal point of the parabola.

  Each heat collection tube 3 is installed at the focal position of the parabola. The heat collecting pipe 3 is a pipe disposed in parallel with the rotation axis of the reflecting mirror 2. The sun rays S are reflected by the reflecting mirror 2 and condensed at the position of the heat collecting tube 3. The heat medium flows in the heat collecting pipe 3 and flows from one end of each heat collecting pipe 3 to the other end. In many cases, the heat collecting tube 3 is disposed in a transparent glass tube only at its light collecting portion.

  FIG. 14 is a schematic view showing a first example of the configuration of a conventional solar heat collecting system.

  The solar heat collecting system of FIG. 14 includes a heat collector 1. The heat collector 1 of FIG. 14 comprises a plurality of reflecting mirrors 2 and a single heat collecting tube 3. FIG. 14 shows six reflecting mirrors 2 a to 2 f for one row as the plurality of reflecting mirrors 2. The solar heat collecting system of FIG. 14 further includes a heat medium flow path 4, a heat medium pump 5, an expansion tank 6, a heater 7 and a temperature sensor 8.

  The heat medium flows in the heat medium channel 4. The heat medium flow path 4 circulates the heat medium by the heat medium pump 5 between the heat collector 1 and the heater 7. The heat medium flow path 4 is constituted by a pipe, and the pipe is covered with a heat insulating material and kept warm.

  The volume of the heat transfer medium changes with the temperature change of the heat transfer medium. The expansion tank 6 is provided at a position higher than the heat medium channel 4 in order to absorb this volume change. In the expansion tank 6, a gas-liquid interface between the gas sealed in the expansion tank 6 and the heat medium (liquid) flowing from the heat medium channel 4 exists. Depending on the type of heat transfer medium, the heat transfer medium in the expansion tank 6 may be open to the atmosphere.

  The heat medium heated by the heat collector 1 is conveyed to the heater 7 and heats the fluid to be heated indicated by the symbol F in the heater 7. For example, when the heat of the heat medium is used for solar thermal power generation, the fluid to be heated is the working fluid of the steam turbine.

  When the heat medium is oil (heat medium oil), when the temperature of the heat medium becomes sufficiently high, the properties of the heat medium deteriorate due to heat denaturation. As a result, the function of the oil as a heat transfer medium is reduced. Further, in the case where the heat medium is water, the heat medium boils if the heat medium locally reaches or exceeds the boiling point. As a result, operation and control of the solar heat collection system become difficult to implement.

  Therefore, the allowable upper limit temperature of the heat transfer medium is determined, and the solar heat collecting system is operated so that the temperature of the heat transfer medium does not reach the allowable upper limit temperature. The allowable upper limit temperature of oil varies depending on the type of oil, but in some cases, it is set to about 300 to 350 ° C. with a margin. On the other hand, the allowable upper limit temperature of water is set in consideration of the boiling point under the pressure at which water is used, and is set to a temperature sufficiently lower than the boiling point with a margin.

In the heat medium channel 4, the position where the heat medium reaches the highest temperature is the outlet of the heat collector 1. Therefore, the temperature sensor 8 in FIG. 14, at a point P ₁ in the vicinity of the outlet of the heat collector 1, is provided so as to insert the temperature sensor 8 to Atsumarinetsukan 3. Point P ₁ is located downstream of the reflecting mirror 2f disposed on the most downstream of the heat collector 1. Temperature sensor 8 measures the temperature of the heat medium flowing through the point P _1. By operating the solar heat collecting system so that the temperature measured by the temperature sensor 8 does not reach the allowable upper limit temperature, the temperature of the heat medium can be maintained lower than the allowable upper limit temperature in the entire solar heat collecting system.

  When the temperature of the heat medium exceeds the allowable upper limit temperature, the solar heat collecting system performs defocusing of the sun beam S by rotationally driving the reflecting mirror 2. The heat collector 1 rotationally drives the reflecting mirror 2 at least to an angle at which the reflected light of the sunlight S is not collected on the heat collecting tube 3. The heating amount of the heat collection tube 3 becomes sufficiently small by defocusing, and the temperature of the heat medium becomes lower than the allowable upper limit temperature.

  When the heat collector 1 is provided with a plurality of rows of reflecting mirrors 2 arranged in parallel, the rotating mirror may be only the row where the temperature of the heat medium exceeds the allowable upper limit temperature, or all the rows May be. Further, the solar heat collecting system may increase the flow rate of the heat medium instead of rotating the reflecting mirror 2 when the temperature of the heat medium exceeds the allowable upper limit temperature, or the heat recovery of the heater 7 The amount may be increased.

  FIG. 15 is a schematic view showing a second example of the configuration of the conventional solar heat collecting system.

Temperature sensor 8 of FIG. 15, at the point P ₂ in the heat collector 1, is provided so as to insert the temperature sensor 8 to Atsumarinetsukan 3. Point P ₂ is located between the reflecting mirror 2f disposed on the most downstream of the heat collector 1, a reflecting mirror 2e adjacent to the reflection mirror 2f. Thus, the temperature sensor 8 may be installed at a point other than the point P ₁ near the outlet of the heat collector 1.

  The temperature control of the heat medium by the allowable upper limit temperature is also applicable to solar heat collection systems other than trough type. For example, defocusing of the reflecting mirror 2 is also applicable to a solar heat collecting system of Fresnel type or tower type. Further, the increase in the flow rate of the heat medium and the increase in the amount of heat recovery of the heater 7 are also applicable to the Fresnel type, the tower type and the fixed panel type.

JP 2012-127607 A

  The temperature control of the heat medium by the allowable upper limit temperature has the following problems.

  The defocusing is performed so that the condensing position of the sunlight S deviates from the focal position of the parabola and the sunlight S does not condense at one place. However, since the heat collecting tube 3 is thick, when the rotation angle of the reflecting mirror 2 is small, most of the sun rays S hit any place on the surface of the heat collecting tube 3 and are collected in the heat collecting tube 3. Therefore, it is necessary to rotationally drive the reflecting mirror 2 to an angle at which the sunlight S is not collected on the heat collecting tube 3. However, since the reflecting mirror 2 is a part having a large weight and size, high speed driving of the reflecting mirror 2 is difficult. Therefore, the heat medium often becomes higher in temperature while the reflecting mirror 2 is rotationally driven. In addition, since the fixed panel type heat collector 1 is not equipped with the reflecting mirror 2, in that case, it is impossible to take measures for reducing the amount of collected light such as defocusing.

  Moreover, there are the following problems in increasing the flow rate of the heat medium. The temperature of the heat transfer medium reaches the allowable upper limit temperature when the temperature of the heat transfer medium tends to rise. Therefore, even if the flow rate of the heat medium is increased, the upward tendency continues only by suppressing the upward tendency. When a sufficient time has elapsed from the increase in the flow rate, the temperature of the heat transfer medium starts to fall and becomes lower than the allowable upper limit temperature. However, by the time the temperature of the heat transfer medium starts to decrease, the temperature of the heat transfer medium may be higher than the allowable upper limit temperature for a long time. In addition, even if the allowable upper limit temperature is set with a margin, the temperature of the heat medium may be higher than the allowable upper limit temperature.

  Further, increasing the heat recovery amount of the heater 7 has the following problems. When the heat recovery amount of the heater 7 is increased, the fluid mass of the heat medium at the outlet of the heater 7 decreases in temperature. When this fluid mass reaches the outlet of the heat collector 1, the temperature of the heat medium at the outlet of the heat collector 1 decreases. However, sufficient time is required for the fluid mass to reach it. Furthermore, the temperature of the heat transfer medium reaches the allowable upper limit temperature when the temperature of the heat transfer medium tends to rise. Therefore, even if the heat recovery amount of the heater 7 is increased, the upward tendency continues only by suppressing the upward tendency. Therefore, even if the allowable upper limit temperature is set with a margin, the temperature of the heat medium may be higher than the allowable upper limit temperature.

  Therefore, it is desirable to surely prevent the temperature of the heat medium from exceeding the allowable upper limit temperature and to prevent the deterioration of the properties of the heat medium.

  Then, this invention makes it a subject to provide the solar-heat-collection system and the cooling-medium supply system which can suppress deterioration of a thermal medium.

  According to one embodiment, a solar heat collection system includes a heat collector for heating a heat medium in a heat collection tube by a solar beam, a heater for heating a fluid to be heated by the heat medium, and the heat collector And a heat medium passage for circulating the heat medium between the heater and the heater. The system is further connected to a first point of the heat collection pipe or the heat medium flow path, and supplies a cooling medium to the first point to mix the cooling medium into the heat medium. Equipped with

It is a schematic diagram which shows the structure of the solar-heat collecting system of 1st Embodiment. It is a schematic diagram which shows the structure of the solar-heat collecting system of the 1st modification of 1st Embodiment. It is a schematic diagram which shows the structure of the solar-heat collecting system of the 2nd modification of 1st Embodiment. It is a schematic diagram which shows the structure of the solar-heat collecting system of the 3rd modification of 1st Embodiment. It is a schematic diagram which shows the structure of the solar-heat collecting system of the 4th modification of 1st Embodiment. It is a schematic diagram which shows the structure of the solar-heat collection system of the 5th modification of 1st Embodiment. It is a schematic diagram which shows the structure of the solar-heat collecting system of 2nd Embodiment. It is a schematic diagram which shows the structure of the solar-heat collecting system of 3rd Embodiment. It is a schematic diagram which shows the structure of the solar-heat collecting system of 4th Embodiment. It is a schematic diagram which shows the structure of the solar-heat collecting system of 5th Embodiment. It is a schematic diagram which shows the structure of the solar-heat collecting system of 6th Embodiment. It is a schematic diagram which shows the structure of the solar-heat collecting system of the modification of 6th Embodiment. It is a schematic diagram which shows the structure of the solar-heat collecting system of 7th Embodiment. It is a schematic diagram which shows the 1st example of a structure of the conventional solar-heat collection system. It is a schematic diagram which shows the 2nd example of a structure of the conventional solar-heat collection system. It is a perspective view which shows the structure of the conventional heat collector.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  In FIG. 1 to FIG. 16, the same or similar components are denoted by the same reference numerals, and overlapping description of each component is omitted. Moreover, when demonstrating the component shown in FIGS. 1-13, the description which overlaps with description of FIGS. 14-16 is abbreviate | omitted.

First Embodiment
FIG. 1: is a schematic diagram which shows the structure of the solar-heat collecting system of 1st Embodiment.

  The solar heat collecting system of FIG. 1 includes a cooling medium tank 11, a cooling medium pump 12, a valve 13, a cooling medium flow path 14, and a control unit 15 in addition to the components shown in FIGS. doing. The cooling medium channel 14 is an example of a first channel. The components 11 to 15 constitute a cooling medium supply system for supplying a cooling medium to the solar heat collecting system.

FIG. 1 shows a point P ₁ near the outlet of the heat collector ₁ and points P ₂ and P ₃ in the heat collector 1. Point P ₁ is located downstream of the reflecting mirror 2f disposed on the most downstream of the heat collector 1. The points P ₂ and P ₃ are located between the reflecting mirror 2 f disposed on the most downstream side of the heat collector 1 and the reflecting mirror 2 e adjacent to the reflecting mirror 2 f. The reflecting mirror 2 f is an example of a first reflecting mirror. The reflecting mirror 2e is an example of a second reflecting mirror. Temperature sensor 8 of this embodiment is inserted at a point P ₂ in Atsumarinetsukan 3, the temperature of the heat medium flowing through the point P ₂ is measured (detected). The temperature sensor 8 is an example of a temperature detector.

One end of the cooling medium channel 14 is connected to the heat collecting pipe ₃ at a point P ₃ , and the other end of the cooling medium channel 14 is connected to the cooling medium tank 11. Point _{P 3} is an example of the first point. The coolant pump 12 and the valve 13 are provided in the coolant channel 14.

The coolant tank 11 stores a coolant. The cooling medium of the present embodiment is a heat medium of the same type as the heat medium flowing through the heat medium channel 4 and is stored at normal temperature. On the other hand, since the heat medium which flows through points P ₂ and P ₃ is heated by the heat collector 1, the temperature is higher than normal temperature. Thus, during operation of the solar heat collecting system, the temperature of the cooling medium is lower than the temperature of the heat medium at the points P ₂ and P ₃ . Thus, the cooling medium can be used to cool the heat medium flowing through the point P _3.

  The control unit 15 controls various operations of the solar heat collecting system. For example, the control unit 15 receives the measured temperature of the heat medium from the temperature sensor 8. Further, the control unit 15 holds the set value of the allowable upper limit temperature of the heat medium.

When the measured temperature of the heat medium reaches the allowable upper limit temperature, the control unit 15 changes the valve 13 from the closed state to the open state, opens the valve 13 and operates the cooling medium pump 12. As a result, the cooling medium in the cooling medium tank 11 is supplied to the point P ₃ via the cooling medium channel 14 by the cooling medium pump 12, it merges into the heat medium flowing through the point P ₃ to (mixed). The heat medium in the heat collection tube 3 is rapidly cooled by joining with a cooling medium having a temperature lower than that of the heat medium. Therefore, the temperature of the heat medium decreases at the point P ₁ where the heat medium reaches the highest temperature. Thereby, the temperature of the heat medium can be returned lower than the allowable upper limit temperature, and the deterioration of the properties of the heat medium can be prevented.

  The total amount of heat medium flowing through the heat medium channel 4 is increased by the merging of the cooling media. This volume increase is absorbed by the expansion tank 6 connected to the heat medium channel 4.

It is desirable that the point P ₃ (junction point) in the heat collector 1 be close to the outlet of the heat collector 1. Because, as the point P ₃ is close to the outlet of the heat collector 1, because a short time can reduce the temperature by the hottest heat medium cooling medium flowing through the point P _1. Therefore, the point P ₃ of the present embodiment is positioned between the reflecting mirror 2f and the reflecting mirror 2e. The reason is that the point between the reflecting mirror 2 f and the reflecting mirror 2 e is closer to the exit of the heat collector 1 than the point between the other reflecting mirrors 2 adjacent to each other.

  Hereinafter, various modifications of the first embodiment will be described with reference to FIGS. 2 to 6. In the present embodiment, the configurations of FIGS. 2 to 6 may be adopted instead of the configuration of FIG. 1.

  FIG. 2: is a schematic diagram which shows the structure of the solar-heat collecting system of the 1st modification of 1st Embodiment.

Temperature sensor 8 of the present modification is inserted in the point P ₁ to Atsumarinetsukan 3 measures the temperature of the heat medium flowing through the point P _1. In this case, the temperature sensor 8 can measure the temperature of the highest temperature heat transfer medium. Therefore, according to the present modification, it is possible to appropriately determine the timing at which the cooling medium should be supplied from the measured temperature of the temperature sensor 8. Incidentally, the point P ₁ may be located upstream of the heat medium flow path 4 from heater 7 downstream of Atsumarinetsukan 3.

  Here, the first embodiment and the first modification will be compared.

Temperature sensor 8 of the first embodiment is inserted at a point P ₂ in Atsumarinetsukan 3 measures the temperature of the heat medium flowing through the point P _2. Therefore, the temperature sensor 8 of the first embodiment measures the temperature of the heat medium upstream of the temperature sensor 8 of the first modification. Therefore, the temperature sensor 8 of the first embodiment can observe the tendency of the temperature change of the heat medium at an earlier timing than the temperature sensor 8 of the first modification. Therefore, according to the first embodiment, the supply of the cooling medium can be quickly started.

Incidentally, the allowable upper limit temperature of the first embodiment, in consideration of the temperature difference between point P ₁ and point P _2, it is desirable to set lower than the upper allowable temperature limit of the first modification. For example, the allowable upper limit temperature of the first modification and _{T 1,} when the upper allowable temperature limit of the first embodiment and _{T 2 (T 1> T 2} ), the control unit 15 of the first embodiment, the point _{P 2} of the temperature of the heat medium by controlling lower than T _2, it is possible to control below T ₁ the temperature of the heat medium at the point P _1. In this case, the value of T ₂ is set in advance based on the value of T ₁ so as to realize such control.

  FIG. 3: is a schematic diagram which shows the structure of the solar-heat collecting system of the 2nd modification of 1st Embodiment.

Temperature sensor 8 of the present modification is plugged into Atsumarinetsukan 3 at point P ₄ in the heat collector 1. Point _{P 4} is located upstream of the point _{P 2} and the point _{P 3.} Thus, the temperature sensor 8 is at the point P ₄ other than the point P _2, it may measure the temperature of the heat medium in the heat collector 1.

  FIG. 4: is a schematic diagram which shows the structure of the solar-heat collecting system of the 3rd modification of 1st Embodiment.

Coolant flow 14 of the present modified example is connected to Atsumarinetsukan 3 at point P ₄ above. Thus, the cooling medium channel 14, at a point P ₄ other than the point P _3, may be merged with the cooling medium to the heat medium in the heat collector 1.

  FIG. 5: is a schematic diagram which shows the structure of the solar-heat collecting system of the 4th modification of 1st Embodiment.

Coolant flow 14 of the present modified example is connected to Atsumarinetsukan 3 at point P ₅ in the vicinity of the inlet of the heat collector 1. Point P ₅ is located upstream of the reflector 2a arranged on the most upstream of the heat collector 1. Incidentally, the point P ₅ may be located downstream of the heat medium flow path 4 from the heat transfer medium pump 5 upstream of Atsumarinetsukan 3.

  FIG. 6: is a schematic diagram which shows the structure of the solar-heat collecting system of the 5th modification of 1st Embodiment.

The heat collector 1 of the present modification includes two rows of reflecting mirrors 2 and two heat collecting tubes 3. The heat medium flow path 4 is branched at points Q ₁ and Q ₂ and connected to the heat collection tubes 3. The reflecting mirrors 2 in each row include six reflecting mirrors 2a to 2f. One of the two temperature sensors 8, reflector 2e in one row are arranged at a point P ₂ between the 2f. The other of the two temperature sensors 8, reflector 2e of the other row are arranged in a point P ₂ between the 2f.

The solar heat collecting system according to the present modification includes a cooling medium tank 11, a cooling medium pump 12, two valves 13, a cooling medium flow path 14 having two branch flow paths, and a control unit 15. doing. One branch channel has one valve 13 is connected to one point P _3. The other branch channel has the other valve 13, is connected to the other point P _3.

  Hereinafter, one of the temperature sensors 8 is referred to as a first temperature sensor 8, and the valve 13 corresponding to the first temperature sensor 8 and the branch flow channel are referred to as a first valve 13 and a first branch flow channel. Further, the other of the temperature sensors 8 is called a second temperature sensor 8, and the valve 13 corresponding to the second temperature sensor 8 and the branch flow path are called a second valve 13 and a second branch flow path.

The control unit 15 opens the first valve 13 and operates the cooling medium pump 12 when the measured temperature of the first temperature sensor 8 reaches the allowable upper limit temperature. As a result, the cooling medium in the cooling medium tank 11 is supplied to one point P ₃ via the first branch flow channel. As a result, the temperature of the heat medium in one of the heat collection tubes 3 decreases.

Further, when the measurement temperature of the second temperature sensor 8 reaches the allowable upper limit temperature, the control unit 15 opens the second valve 13 and operates the cooling medium pump 12. As a result, the cooling medium in the cooling medium tank 11 is supplied to the other point P ₃ via a second branch flow path. As a result, the temperature of the heat medium in the other heat collecting tube 3 is lowered.

  In addition, the heat collector 1 of this modification may be equipped with three or more rows of reflecting mirrors 2 and three or more heat collecting tubes 3. In this case, it is desirable to provide the temperature sensor 8, the valve 13, and the branch flow path in all the rows. Further, it is desirable that the control unit 15 lowers the temperature of the heat medium in the corresponding heat collection tube 3 by opening only the corresponding valve 13 when the measured temperature of a certain temperature sensor 8 reaches the allowable upper limit temperature.

  As described above, the solar heat collecting system according to the present embodiment includes the cooling medium flow path 14 that supplies the cooling medium to the heat collecting pipe 3 or the heat medium flow path 4 and mixes the cooling medium into the heat medium. . Therefore, according to the present embodiment, it is possible to suppress the deterioration of the heat medium by reducing the temperature of the heat medium by the cooling medium.

  The solar heat collecting system of the present embodiment may be other than the trough type, and may be, for example, a Fresnel type, a tower type, or a fixed panel type. The same applies to the second to seventh embodiments described later. The first to fifth modifications may be combined with each other and applied to the first embodiment. In addition, the first to fifth modifications may be applied to second to seventh embodiments described later singly or in combination with each other.

Second Embodiment
FIG. 7 is a schematic view showing the configuration of the solar heat collecting system of the second embodiment.

  The solar heat collecting system of FIG. 7 includes a valve 16 and a cooling medium channel 17 in addition to the components shown in FIG. 1. The cooling medium channel 17 is an example of a second channel.

Figure 7 shows a point P ₆ on the heat medium flow path 4. The point P ₆ is located downstream of the heat medium pump 5 between the heat collector 1 and the heat medium pump 5. One end of the cooling medium passage 17 is connected to the heat medium passage 4 at a point P ₆ , and the other end of the cooling medium passage 17 is connected to the cooling medium tank 11. Point _{P 6} is an example of the second point. The valve 16 is provided in the cooling medium channel 17.

When the measured temperature of the heat medium reaches the allowable upper limit temperature, the control unit 15 changes the valves 13 and 16 from the closed state to the open state, opens the valves 13 and 16, and operates the cooling medium pump 12. As a result, the cooling medium in the cooling medium tank 11 is supplied to the point P ₃ via a cooling medium flow passage 14, the heat medium in the Atsumarinetsukan 3 is lowered temperatures. Furthermore, the heat medium at point P ₆ is supplied into the cooling medium tank 11 via the cooling medium channel 17. The amount of the heat medium flowing from the point P ₆ to the cooling medium tank 11 is the same amount of cooling medium flowing out from the cooling medium tank 11 to a point P _3. Heat medium having flowed into the cooling medium tank 11 from the point P ₆ is used as a cooling medium.

Since the point P ₆ downstream from the heater 7, the heat medium from the point P ₆ is sufficiently low temperature than the heat medium point P _3. However, the heat medium from the point P ₆ are sufficiently high temperature than previously stored cold heat medium in the cooling medium tank 11 (cooling medium). Therefore, in the present embodiment, the heat medium flows from the cooling medium passage 17 to the top of the cooling medium tank 11 and the heat medium flows out from the bottom of the cooling medium tank 11 to the cooling medium passage 14. It is desirable that the heat medium in 11 be temperature stratified. As a result, even if the depth of the cooling medium tank 11 in the vertical direction is not sufficiently deep, a heat medium at normal temperature can be supplied to the heat collection tube 3 until the defocusing of the heat collector 1 is completed.

Incidentally, the point P ₆ is located downstream of the heat transfer medium pump 5 7, may be located upstream of the heat transfer medium pump 5. Further, the point P ₆ can be located on Atsumarinetsukan 3.

When opening the valve 13 and 16, since the flow rate of the heat medium in the region between the inlet and the point P ₃ of the heat collector 1 is reduced, the temperature of the heat medium in this region is increased. However, since the effect of ambient temperature of the cooling medium to the point P ₃ is injected is large, the heat medium in the region between the outlet point P ₃ and the heat collector 1 is sufficiently cooled.

  Here, the first embodiment and the second embodiment will be compared.

  In the first embodiment, in order to sufficiently cool the heat medium in the heat collector 1, the cooling medium tank 11 is released to the atmosphere, or the cooling medium pump 12 is set to a high output to generate a large amount of heat from the cooling medium tank 11. A large amount of medium needs to be drained. On the other hand, in the second embodiment, the heat medium in the heat collector 1 can be sufficiently cooled regardless of such a method.

Third Embodiment
FIG. 8 is a schematic view showing the configuration of the solar heat collecting system of the third embodiment.

The solar heat collecting system of FIG. 8 comprises the components shown in FIG. 7 but without the coolant pump 12. Thus, the cooling medium in the cooling medium tank 11 is supplied to the point P ₃ without passing through a cooling medium pump 12.

  Here, the second embodiment and the third embodiment will be compared.

In the second embodiment, sufficient pressure loss of the coolant flow 14 and 17 is small and, when the cooling medium is sufficiently small vertical height between the pump 12 and the point P _3, the cooling medium tank 11 it can be sent to the point P ₃ of the cooling medium without using a cooling medium pump 12. Thus, the solar heat collecting system of the third embodiment is configured by removing the cooling medium pump 12 from the solar heat collecting system of the second embodiment.

In the present embodiment, the point P ₆ is located downstream of the heat medium pump 5. As a result, the heat medium in the cooling medium channels 14 and 17 can be transported by the transfer capacity of the heat medium pump 5. According to the present embodiment, by configuring the solar heat collecting system without using the cooling medium pump 12, it is possible to simplify the configuration of the solar heat collecting system.

Fourth Embodiment
FIG. 9 is a schematic view showing the configuration of the solar heat collecting system of the fourth embodiment.

The solar heat collecting system of FIG. 9 includes the components shown in FIG. 8 but does not include the cooling medium tank 11, the valve 16, and the cooling medium flow path 17. Further, one end of the coolant flow field 14 is connected to the point P _3, the other end portion of the coolant flow field 14 is connected to the point P _6. Accordingly, the heat medium of the heat medium flow path 4 flows from the point P ₆ to the coolant passage 14, is supplied as a cooling medium to the point P ₃ without passing through a cooling medium tank 11 and the coolant pump 12.

  Here, the third embodiment and the fourth embodiment will be compared.

In the third embodiment, when the temperature of the heat medium flowing through the point P ₆ is sufficiently temperature drop, there is no need to cool in the heat medium cooling medium tank 11. The temperature of the heat medium is not a normal temperature but, if sufficiently low temperature than the temperature of the heat medium flowing through the point P _3, the heat medium is because it functions well as a cooling medium. Therefore, the solar heat collecting system of the fourth embodiment is configured by removing the cooling medium tank 11 from the solar heat collecting system of the third embodiment.

  According to this embodiment, by configuring the solar heat collecting system without using the cooling medium tank 11, the configuration of the solar heat collecting system can be further simplified.

Fifth Embodiment
FIG. 10 is a schematic view showing the configuration of the solar heat collecting system of the fifth embodiment.

The solar heat collecting system of FIG. 10 comprises the components shown in FIG. 8 but without the coolant reservoir 11 and the valve 16. Further, one end of the cooling medium channel 14 is connected to the point P _3, and the other end of the cooling medium channel 14 is connected to the expansion tank 6. Further, one end of the cooling medium channel 17 is connected to a point P ₇ on the heat medium channel 4, and the other end of the cooling medium channel 17 is connected to the expansion tank 6. The point P ₇ is located upstream of the heat medium pump 5 between the heater 7 and the heat medium pump 5. Point _{P 7} is an example of the second point. Thus, the expansion tank 6 of the present embodiment is in communication with the cooling medium channels 14 and 17.

When the volume of the heat medium flowing through the heat medium channel 4 increases, the heat medium flows from the point P ₇ into the expansion tank 6 via the cooling medium channel 17. Thereby, the volume increase of the heat medium is absorbed by the expansion tank 6.

When the measured temperature of the heat medium reaches the allowable upper limit temperature, the control unit 15 changes the valve 13 from the closed state to the open state, opens the valve 13 and operates the cooling medium pump 12. As a result, the heat medium in expansion tank 6 is supplied as a cooling medium to the point P ₃ via a cooling medium flow passage 14, the heat medium in the Atsumarinetsukan 3 is lowered temperatures. Furthermore, the heat medium at the point P ₇ flows into the expansion tank 6 via the cooling medium channel 17.

  In the fourth embodiment, the heat medium of the heat medium channel 4 is immediately used as a cooling medium, whereas in the present embodiment, the heat medium of the heat medium channel 4 is stored in the expansion tank 6 and then cooled. Use as a medium. Therefore, in the present embodiment, a heat medium having a temperature lower than that of the fourth embodiment can be used as a cooling medium. Further, the temperature of the heat medium in the expansion tank 6 is generally different from the temperature of the heat medium flowing through the heat medium channel 4 and is close to normal temperature, so it is easy to reduce the temperature. Therefore, in the present embodiment, the cooling medium tank 11 becomes unnecessary.

  The outlet of the expansion tank 6 (the connection point between the expansion tank 6 and the cooling medium channel 14) is disposed far from the inlet of the expansion tank 6 (the connection point between the expansion tank 6 and the cooling medium channel 17). Is desirable. As a result, it is possible to avoid that the fluid lump that has flowed into the expansion tank 6 from the inlet immediately flows out of the outlet of the expansion tank 6.

Further, the point P ₇ is located upstream of the heat transfer medium pump 5 in FIG. 10 may be located downstream of the heat transfer medium pump 5.

Sixth Embodiment
FIG. 11 is a schematic view showing the configuration of the solar heat collecting system of the sixth embodiment.

  The solar heat collecting system of FIG. 11 comprises the components shown in FIG. 1 but does not comprise the coolant tank 11, the coolant pump 12, the valve 13 and the coolant channel.

The heat medium flow path 4 of FIG. 11 includes a bypass flow path 21 that bypasses the heat collector 1 and circulates the heat medium. Bypass passage 21 is branched from the main flow of the heat medium flow path 4 at point R _1, and joins the main stream of the heat medium flow path 4 at the point R _2. The bypass channel 21 is provided with a heat medium pump 22, a valve 23 located upstream of the heat medium pump 22, and a valve 24 located downstream of the heat medium pump 22. The heat medium that has flowed into the bypass flow path 21 from the point R ₁ is transported by the heat medium pump 22 to the point R ₂ . Further, the valve 27 is provided in the heat medium flow channel 4 between the point R ₁ and the heat collector 1, and the valve 28 is provided in the heat medium flow channel 4 between the point R ₂ and the heat collector 1 It is done. Further, the flow path 29 is provided to bypass the heat medium pump 22, and the valve 30 is provided in the flow path 29.

The solar heat collecting system of FIG. 11 has a cooling medium channel 25 instead of the cooling medium channel 14. One end of the coolant flow field 25 is connected to the bypass passage 21 at a point R ₃ on the bypass flow path 21, the other end portion of the cooling medium flow passage 25, at the point P ₃ It is connected to the heat collecting pipe 3. The point R ₃ is located downstream of the heat medium pump 22 between the heat medium pump 22 and the valve 24. Coolant flow 25 is supplied to the point P ₃ heat medium from the point R ₃ as a cooling medium. The cooling medium channel 25 is an example of a first channel. Point _{P 3} is an example of the first point. Point _{R 3} is an example of the second point. The coolant flow path 25 is provided with a valve 26.

  During heat collecting operation of the solar heat collecting system, the valves 23, 24, 26 are closed and the valves 27, 28 are opened. In this case, the heat medium flows in the heat collector 1 and does not flow in the bypass channel 21. The valve 30 may be closed or open.

In addition, when the solar heat collecting system is switched from the heat collecting operation to the bypass operation for some reason, one or both of the valves 27, 28 are closed after the valves 23, 24, 30 are opened. In this case, the heat medium flows through the bypass flow path 21 from the point R ₁ bypass the heat collector 1 to the point R _2.

During heat collection operation of the solar heat collection system, a heat medium at normal temperature is stored in the bypass flow passage 21. When the measured temperature of the heat medium reaches the allowable upper limit temperature, the control unit 15 opens the valves 23 and 26 and closes the valve 30, with the valve 24 closed and the valves 27 and 28 kept open, and the heat medium pump Activate 22 As a result, the normal temperature of the heat medium in the bypass flow path 21, the heat transfer medium pump 22 is supplied as a cooling medium to the cooling medium flow passage 25 through the point R _3, it merges into the heat medium flowing through the point P _3. Furthermore, the heat medium flows from the point R ₁ in the bypass passage 21. The amount of the heat medium flowing from the point R ₁ into the bypass channel 21 is the same as the amount of the heat medium flowing from the bypass channel 21 to the cooling medium channel 25.

When opening the valve 23 and 26, since the flow rate of the heat medium in the region between the inlet and the point P ₃ of the heat collector 1 is reduced, the temperature of the heat medium in this region is increased. However, since the effect of ambient temperature of the cooling medium to the point P ₃ is injected is large, the heat medium in the region between the outlet point P ₃ and the heat collector 1 is sufficiently lowered temperature.

  Generally, the temperature of the heat medium in the bypass flow passage 21 is close to normal temperature except during the bypass operation or immediately after the bypass operation. Therefore, in the present embodiment, the cooling medium tank 11 becomes unnecessary. Further, the lengths of the bypass flow channel 21 and the cooling medium flow channel 25 of the present embodiment are generally the lengths of the cooling medium flow channel 14 of the first to fifth embodiments and the second, third, and fifth embodiments. The length is shorter than the length of the coolant channel 17. Therefore, the required power of the heat medium pump 22 of the present embodiment is smaller than the required power of the cooling medium pump 12 of the first embodiment and the like.

  FIG. 12 is a schematic view showing the configuration of a solar heat collecting system according to a modification of the sixth embodiment.

The heat collector 1 of this modification is equipped with the reflective mirror 2 of 2 rows, and the two heat collector tubes 3 similarly to the above-mentioned 5th modification. The heat medium flow path 4 is branched at points Q ₁ and Q ₂ and connected to the heat collection tubes 3. The reflecting mirrors 2 in each row include six reflecting mirrors 2a to 2f. One of the two temperature sensors 8, reflector 2e in one row are arranged at a point P ₃ between the 2f. The other of the two temperature sensors 8, reflector 2e of the other row are arranged at a point P ₃ between the 2f.

  The solar heat collecting system according to the present modification includes two sets of bypass flow paths 21, a heat medium pump 22, a cooling medium flow path 25, valves 23, 24, 26, 27, 28, 30 and a flow path 29. There is. The configuration of each set of bypass channels 21 and the like is the same as the configuration shown in FIG. When the measured temperature of a certain temperature sensor 8 reaches the allowable upper limit temperature, the control unit 15 opens only the corresponding valve 23, 26 and closes only the corresponding valve 30, and operates only the corresponding heat medium pump 22. , The temperature of the heat medium in the corresponding heat collecting tube 3 is reduced.

  The solar heat collecting system of this modification includes only one set of the bypass flow passage 21, the heat medium pump 22, the valves 23, 24, 27, 28, 30 and the flow passage 29, and the cooling medium flow passage 25 and Two sets of valves 26 may be provided. In this case, two coolant channels 25 branch from one bypass channel 21, and one valve 26 is provided in each coolant channel 25. The control unit 15 opens the valve 23 and closes the valve 30, opens the valve 26 corresponding to the temperature sensor 8, and operates the heat medium pump 22 when the measured temperature of a certain temperature sensor 8 reaches the allowable upper limit temperature. Thus, the temperature of the heat medium in the corresponding heat collecting tube 3 is reduced.

  Moreover, the heat collector 1 of this modification may be equipped with three or more rows of reflecting mirrors 2 and three or more heat collecting tubes 3. In this case, as in the above-described two-row example, one set of bypass channels 21 may be individually provided in each column, or one set of bypass channels 21 may be commonly provided in a plurality of columns. May be In addition, one solar heat collecting system may be combined with these configurations. In the case where one set of bypass flow channels 21 and the like are commonly provided in a plurality of rows, the plurality of cooling medium flow channels 25 are branched from one bypass flow channel 21, and one valve is provided in each cooling medium flow channel 25. 26 is provided. In any of the configurations, the control unit 15 opens the valve 26 corresponding to at least the temperature sensor 8 when the measured temperature of the certain temperature sensor 8 reaches the allowable upper limit temperature, so that the heat medium in the corresponding heat collection tube 3 Reduce the temperature.

  As described above, the solar heat collecting system according to the present embodiment includes the cooling medium flow path 25 that supplies the cooling medium to the heat collecting pipe 3 or the heat medium flow path 4 and mixes the cooling medium into the heat medium. . Therefore, according to the present embodiment, it is possible to suppress the deterioration of the heat medium by cooling the heat medium with the cooling medium.

  The above modification of the sixth embodiment may be applied to the seventh embodiment described later.

Seventh Embodiment
FIG. 13 is a schematic view showing a configuration of a solar heat collecting system according to a seventh embodiment.

The solar heat collecting system of FIG. 13 comprises the components shown in FIG. 12 but does not comprise the heating medium pump 22, the flow passage 29 and the valve 30. Accordingly, the heat medium having flowed from the point R ₁ in the bypass passage 21 is fed to the point R ₂ and the point R ₃ not through the heat transfer medium pump 22.

  Here, the sixth embodiment and the seventh embodiment will be compared.

In the sixth embodiment, when the pressure loss in the bypass flow passage 21 and the cooling medium flow passage 25 is sufficiently small, and the vertical height between the heat medium pump 5 and the point P ₃ is sufficiently small, the bypass flow The heat medium in the passage 21 can be sent to the point R ₂ or the point R ₃ without using the heat medium pump 22. Therefore, the solar heat collecting system of the seventh embodiment is configured by removing the heat medium pump 22 from the solar heat collecting system of the sixth embodiment.

  In the present embodiment, the heat medium in the bypass flow path 21 and the cooling medium flow path 25 is transported by the transfer capacity of the heat medium pump 5. According to the present embodiment, by configuring the solar heat collecting system without using the heat medium pump 23, it is possible to simplify the configuration of the solar heat collecting system.

  While certain embodiments have been described above, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. The novel systems described herein may be implemented in various other forms. In addition, various omissions, substitutions, and changes can be made to the form of the system described in the present specification without departing from the scope of the invention. The appended claims and their equivalents are intended to cover such forms and modifications as would fall within the scope and spirit of the invention.

1: Heat collector, 2: Reflector, 3: Heat collector, 4: Heat medium flow path,
5: heat medium pump, 6: expansion tank, 7: heater, 8: temperature sensor,
11: Coolant tank, 12: Coolant pump, 13: Valve,
14: Coolant channel, 15: Controller, 16: Valve, 17: Coolant channel,
21: bypass flow path, 22: heat medium pump, 23: valve, 24: valve,
25: cooling medium flow channel, 26: valve, 27: valve, 28: valve, 29: flow channel, 30: valve

Claims (14)

A heat collector that heats the heat medium in the heat collection tube with a sunlight,
A heater for heating a fluid to be heated by the heat medium;
A heat medium channel for circulating the heat medium between the heat collector and the heater;
A first flow path connected to a first point of the heat collection pipe or the heat medium flow path, supplying a cooling medium to the first point, and mixing the cooling medium into the heat medium;
Equipped with
A solar heat collecting system characterized in that the first point is located between a first reflecting mirror disposed at the most downstream of the heat collector and a second reflecting mirror adjacent to the first reflecting mirror. .   The solar heat collecting system according to claim 1, wherein the cooling medium has a temperature lower than the temperature of the heat medium at the first point. A temperature detector for detecting the temperature of the heat medium;
A control unit configured to supply the cooling medium from the first flow path to the first point based on the temperature detected by the temperature detector;
The solar heat collection system according to claim 1 or 2 , characterized by comprising. It said temperature detector, between said first reflector and said second reflector, or in the upstream of the heater downstream of the first reflecting mirror, and characterized in that for detecting the temperature of the heating medium The solar heat collection system according to claim 3 . A coolant tank storing the coolant;
The solar heat collecting system according to any one of claims 1 to 4 , wherein the first flow path supplies the cooling medium in the cooling medium tank to the first point. A second flow path is connected to the heat medium flow path or the second point of the heat collection pipe, and supplies the heat medium from the second point to the cooling medium tank as the cooling medium. The solar heat collection system according to claim 5 , wherein 6. The cooling medium pump according to claim 5 , further comprising: a cooling medium pump provided in the first flow path and supplying the cooling medium in the cooling medium tank to the first point via the first flow path. The solar heat collecting system according to 6 . The first flow path, the cooling medium, characterized in that it is supplied to the first point without passing through a cooling medium pump, solar heat collection system according to claim 5 or 6 of the cooling medium tank. The first flow path is connected to the heat medium flow path or a second point of the heat collection pipe, and the heat medium from the second point is not used as a cooling medium but via a cooling medium tank and a cooling medium pump. The solar heat collecting system according to any one of claims 1 to 4 , characterized in that the first point is supplied to the first point. An expansion tank in communication with the heat medium channel or a channel connected to a second point of the heat collection pipe,
The solar heat collecting system according to any one of claims 1 to 4 , wherein the first flow path supplies the heat medium in the expansion tank as the cooling medium to the first point. . The heat medium flow path includes a bypass flow path that bypasses the heat collector and allows the heat medium to flow.
The first flow path is connected to a second point of the bypass flow path, and the heat medium from the second point is supplied to the first point as the cooling medium. The solar heat collection system according to any one of 1 to 4 . The solar heat collecting system according to claim 11 , further comprising: a heat medium pump provided in the bypass flow path and supplying the heat medium flowing into the bypass flow path to the second point. The solar heat collecting system according to claim 11 , wherein the bypass channel supplies the heat medium having flowed into the bypass channel to the second point without passing through a heat medium pump. A heat collector that heats the heat medium in the heat collection tube with a sunlight,
A heater for heating a fluid to be heated by the heat medium;
A heat medium channel for circulating the heat medium between the heat collector and the heater;
A cooling medium supply system for supplying a cooling medium to a solar heat collecting system comprising:
A first flow path connected to a first point of the heat collection pipe or the heat medium flow path, supplying the cooling medium to the first point, and mixing the cooling medium into the heat medium;
A valve provided in the first flow path and controlling supply of the heat medium from the first flow path to the first point;
Equipped with
The cooling medium supply system according to claim 1, wherein the first point is located between a first reflecting mirror disposed at the most downstream of the heat collector and a second reflecting mirror adjacent to the first reflecting mirror. .

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