JP2017067360A - Steam generation device - Google Patents

Abstract

Heat is stored in a short time while generating steam in a steam generator. In a steam generator 1, a heat medium continuously circulates along a circulation path 33 that returns from the heat medium tank 30 to the heat medium tank 30 through the steam generator 31 and the solar light collector 2 in order. To do. The solar concentrator 2 heats the heat medium with the concentrated sunlight, and the steam generator 31 generates liquid vapor by heating the liquid using the heat medium. A bypass channel 340 is provided that connects a branch position between the heat medium tank 30 and the steam generator 31 in the circulation path 33 and a joining position 344 between the steam generator 31 and the solar light collecting device 2. The heat medium that has passed through the steam generator 31 is mixed with the heat medium that has passed through the bypass flow path 340 and sent to the solar light collector 2. Thereby, when the amount of solar radiation is large, the temperature of the heat transfer medium oil in the heat transfer medium tank 30 can be raised in a short time while generating steam in the steam generator 31 to store heat. [Selection] Figure 1

Description

  The present invention relates to a steam generator using sunlight.

  In recent years, a technique for collecting solar thermal energy by concentrating sunlight and heating a heat medium has been put into practical use. In the steam generation apparatus according to the technology, steam is generated using concentrated sunlight, and the steam is used for various purposes.

  On the other hand, since solar radiation, which is a heat source, changes depending on the weather, time zone, and the like, a heat accumulator or the like is used in the steam generator. For example, Patent Document 1 discloses a solar thermal steam cycle system having a heat collector, a heat accumulator, a feed water heater, an evaporator, and the like. In this system, when the amount of heat stored in the regenerator is larger than a predetermined standard, the flow rate adjusting valve is set so that the flow rate of the heat medium from the regenerator to the evaporator is larger than the flow rate from the regenerator to the feed water heater. The opening command value is determined. In addition, when the heat storage amount is smaller than a predetermined reference, the flow rate adjustment valve opening command value so that the flow rate of the heat medium from the heat storage device to the evaporator is smaller than the flow rate from the heat storage device to the feed water heater. Is determined.

  In the solar thermal power plant described on page 18 of Non-Patent Document 1, a solar concentrator, a high-temperature molten salt storage tank, a steam generator, and a low-temperature molten salt storage tank are provided. Circulate.

International Publication No. 2012/120556

Rafael Osuna Gonzalez-Aguillar et al., "Concentrating solar power-From research to implementation", European Commission, 2007

  By the way, in the apparatus of Patent Document 1, since all of the heat medium from the heat accumulator is used for generation of steam or heating of water supply, it is difficult to store heat in a short time while generating steam.

  This invention is made | formed in view of the said subject, and it aims at storing heat in a short time, generating a vapor | steam in a steam generator.

  Invention of Claim 1 is a steam generator using sunlight, Comprising: The solar light collector which heats a heat medium with the condensed sunlight, The heat-medium tank which stores the said heat medium, Storing a liquid and heating the liquid using the heat medium to generate a vapor of the liquid; and the steam generator and the solar light collecting device from the heat medium tank. A pump that continuously circulates the heating medium along a circulation path that returns to the heating medium tank in order, a branch position between the heating medium tank and the steam generator in the circulation path, and the steam A bypass flow path connecting a generator and a confluence position between the solar light collecting device and mixing the heat medium that has passed through the steam generator with the heat medium that has passed through the bypass flow path And a heating medium mixing section to be sent to the solar concentrator Obtain.

  Invention of Claim 2 is the steam generator of Claim 1, Comprising: The said heat-medium mixing part is a temperature sensor which measures the temperature of the said heat medium in the said circulation path, and the said branch position is the said The apparatus further includes a flow rate adjusting unit that adjusts a first flow rate of the heat medium flowing through the steam generator and a second flow rate of the heat medium flowing through the bypass flow path based on a measurement value of the temperature sensor.

  Invention of Claim 3 is a steam generator of Claim 2, Comprising: The said temperature sensor measures the temperature of the said heat medium which goes to the said sunlight condensing device from the said confluence | merging position, The said flow volume The adjustment unit adjusts the first flow rate and the second flow rate so that the measured value of the temperature sensor becomes a predetermined temperature.

  Invention of Claim 4 is a steam generator in any one of Claim 1 thru | or 3, Comprising: The temperature of the said heating medium which passed the said solar condensing apparatus is the said inside of the said heating medium tank. Even when the temperature is lower than the temperature of the heat medium, the heat medium flows into the heat medium tank from the solar light collecting device.

  A fifth aspect of the present invention is the steam generator according to any one of the first to fourth aspects, wherein the heat medium tank is the only tank for the heat medium in the circulation path.

  Invention of Claim 6 is a steam generator in any one of Claim 1 thru | or 5, Comprising: In the external installation to which the said steam generated with the said steam generator is supplied, a steam is generated with fuel An auxiliary boiler is provided.

  According to the present invention, heat can be stored in the heat medium tank in a short time while supplying steam to the external equipment when the amount of solar radiation is large, and steam is supplied to the external equipment for a certain period even when the amount of solar radiation is small. can do.

It is a figure which shows the structure of a steam generator. It is a figure which shows the structure of a sunlight condensing device. It is a figure which shows the flow of operation | movement of a heat medium mixing part. It is a figure which shows the temperature change of the heat-medium oil in the case of the heat storage in a heat-medium tank. It is a figure which shows the temperature change of the heat-medium oil in the case of the thermal radiation in a heat-medium tank. It is a figure which shows the steam generator of a comparative example.

  FIG. 1 is a diagram showing a configuration of a steam generator 1 according to an embodiment of the present invention. The steam generator 1 is a device that heats a predetermined heat medium (HTF: Heat Transfer Fluids) using sunlight and generates water vapor using the heat medium. The steam generator 1 is used, for example, in a seawater desalination plant (fresh water plant) that generates fresh water by steam heating of seawater.

  The steam generator 1 includes a solar light collector 2, a heat medium tank 30, a steam generator 31, a pump 32, a heat medium mixing unit 34, a steam supply path 41, and a pressure adjusting unit 42. . The heat medium tank 30 stores heat medium oil that is a heat medium. In a preferred heat medium tank 30, an inert gas such as nitrogen gas is enclosed in order to suppress oxidation of the heat medium oil. If necessary, the inside of the heating medium tank 30 may be pressurized. The steam generator 31 stores a liquid of water and heats the water using heat transfer oil to generate water vapor. The heat medium tank 30 and the steam generator 31 are provided in a circulation path 33 for circulating the heat medium oil between the heat medium tank 30, the steam generator 31 and the solar light collecting device 2.

  The pump 32 is provided between the heat medium tank 30 and the steam generator 31 in the circulation path 33. The pump 32 feeds the heat medium oil in the heat medium tank 30 toward the steam generator 31 at an approximately constant flow rate, and the heat medium oil that has passed through the steam generator 31 and the solar light collector 2 is heated. Return to medium tank 30. In this way, the pump 32 continuously circulates the heat medium oil along the circulation path 33 that returns from the heat medium tank 30 to the heat medium tank 30 via the steam generator 31 and the solar light collecting device 2 in order. . As will be described later, some heat transfer oil may not pass through the steam generator 31. If the heat transfer oil can be circulated, the pump 32 may be arranged at another position in the circulation path 33.

  In the circulation path 33, a flow rate adjustment valve 341 of the heat medium mixing unit 34 is provided between the heat medium tank 30 and the steam generator 31 (between the pump 32 and the steam generator 31 in FIG. 1). The flow rate adjustment valve 341 is a three-way valve, and the position of the flow rate adjustment valve 341 is a branch position in the circulation path 33. A merging position 344 is set between the steam generator 31 and the solar light collecting device 2 in the circulation path 33. The heat medium mixing unit 34 further includes a bypass channel 340 that connects the flow rate adjustment valve 341 (branch position) and the junction position 344. The flow rate adjustment valve 341 has a flow rate (hereinafter referred to as a “first flow rate”) at which the heat transfer oil sent by the pump 32 flows from the branch position to the steam generator 31 along the circulation path 33 and generates steam. It is possible to adjust the ratio with the flow rate (hereinafter referred to as “second flow rate”) that flows through the bypass flow path 340 while avoiding the vessel 31. The heat medium oil that has passed through the steam generator 31 is mixed with the heat medium oil that has passed through the bypass flow path 340 by the heat medium mixing unit 34 and is sent to the solar light collector 2.

  In the circulation path 33, a temperature sensor 334 is provided between the flow rate adjustment valve 341 and the steam generator 31, and a temperature sensor 335 is provided between the steam generator 31 and the merge position 344, and the merge position A temperature sensor 342 is provided between the 344 and the solar light collecting device 2. The temperature sensor 334 measures the temperature of the heat transfer oil just before flowing into the steam generator 31, and the temperature sensor 335 measures the temperature of the heat transfer oil just after flowing out of the steam generator 31. The temperature of the heat transfer oil toward the solar light collector 2 from the merge position 344 by the temperature sensor 342 (as will be described later, the temperature of the heat transfer oil at the entrance of the solar light collector 2, that is, the solar light collector 2 Is the temperature of the heat transfer oil before it is heated, and is hereinafter referred to as “temperature before heating”). The heat medium mixing unit 34 further includes a heat medium mixing control unit 343. In the heat medium mixing unit 34, a measured value of the temperature before heating of the heat medium oil (that is, the temperature of the heat medium oil after mixing) acquired by the temperature sensor 342 is input to the heat medium mixing control unit 343, and the heat medium mixing The control unit 343 controls the flow rate adjustment valve 341 according to the measurement value. Details of control of the flow rate adjustment valve 341 in the heat medium mixing unit 34 will be described later.

  In the circulation path 33, a pressure sensor 331 and a valve (check valve) 332 are provided between the pump 32 and the flow rate adjustment valve 341. The pressure sensor 331 measures the pressure of the heat transfer oil due to the liquid feeding by the pump 32. For example, in the circulation path 33, another path arranged in parallel is provided for a portion including the combination of the pump 32, the pressure sensor 331, and the check valve 332, and the same combination as the above combination is provided in the path. May be. In this case, during the maintenance of one pump 32, the steam generator 1 can be continuously operated using the other pump 32 (the same applies to the pump 521 described later).

  The heat medium tank 30 is provided with a level sensor 301. The position of the liquid level in the heat medium tank 30 is measured by the level sensor 301. The steam generator 31 is provided with a pressure sensor 422 and a level sensor 311. The pressure sensor 422 is a part of the pressure adjusting unit 42, and the internal pressure (steam pressure) of the steam generator 31 is measured by the pressure sensor 422. The position of the liquid level in the steam generator 31 is measured by the level sensor 311. One end of a steam supply path 41 is connected to the upper part of the steam generator 31.

  The steam supply path 41 connects the steam generator 31 and the external equipment 9. When the steam generator 1 is used in a seawater desalination plant, the external equipment 9 includes a seawater heater and the like, and the steam supply path 41 is connected to the heater. The external equipment 9 has an auxiliary boiler 91 that generates steam with fuel, and can supply the steam from the auxiliary boiler 91 to the heater. Information such as measured values of each sensor in the steam generator 1 is input to a control unit (not shown) of the external equipment 9, and the auxiliary boiler 91 and the like are controlled according to the information.

  In the steam supply path 41, a pressure control valve 421, a temperature sensor 411, a pressure sensor 412, and a flow rate sensor 413 are provided from the steam generator 31 toward the external equipment 9. The temperature, pressure, and flow rate of the steam flowing through the steam supply path 41 are measured by the temperature sensor 411, the pressure sensor 412, and the flow rate sensor 413, respectively. The pressure control valve 421 is a part of the pressure adjustment unit 42. The pressure adjustment unit 42 further includes an internal pressure control unit 423. The measured value of the internal pressure of the steam generator 31 acquired by the pressure sensor 422 is input to the internal pressure control unit 423. In the internal pressure control unit 423, the pressure control valve 421 is controlled according to the measured value so that the internal pressure of the steam generator 31 maintains a predetermined set pressure (for example, 1.0 MPa (megapascal)). The set pressure is a pressure set in order to use steam in the external equipment 9. Note that the order of the plurality of components provided in the steam supply path 41 may be changed as appropriate.

  The steam generator 1 further includes a water supply tank 51, a water supply path 52, and a water supply flow rate control unit 53. The water supply tank 51 stores water for water supply. The water supply path 52 connects the water supply tank 51 to the steam generator 31. In the water supply path 52, a pump 521, a pressure sensor 522, a valve (check valve) 523, a temperature sensor 524, a flow rate sensor 525, and a flow rate control valve 526 are provided in order from the water supply tank 51 toward the steam generator 31. The pressure sensor 522 measures the pressure of water due to the liquid feeding by the pump 521. The temperature sensor 524 and the flow rate sensor 525 measure the temperature and flow rate of the water flowing through the water supply channel 52, respectively.

  A measured value of the flow rate of steam flowing through the steam supply path 41 and a measured value of the liquid level in the steam generator 31 are input to the feed water flow rate control unit 53 from the flow rate sensor 413 and the level sensor 311, respectively. Based on these measured values, the feed water flow rate control unit 53 controls the flow rate control valve 526 so that the position of the liquid level in the steam generator 31 is constant.

  FIG. 2 is a diagram illustrating a configuration of the solar light collecting device 2. In FIG. 2, the heat medium tank 30 and the pump 32 provided in the circulation path 33 are shown by blocks. The solar light collecting device 2 is a so-called Fresnel type light collecting device, and heats the heat transfer oil with the condensed sunlight. The solar light collecting device 2 includes a large number of mirrors 21 and a heat recovery tube 22. Inside the heat recovery pipe 22, the heat medium oil sent from the heat medium tank 30 by the pump 32 flows, and a large number of mirrors 21 concentrate the sunlight on the heat recovery pipe 22, thereby recovering heat. The heat transfer oil in the tube 22 is heated. The heat medium oil heated by the solar light collecting device 2 is returned to the heat medium tank 30 via the circulation path 33. The temperature of the heat transfer oil that has passed through the solar light collector 2 is measured by the temperature sensor 336. In the preferable steam generator 1, a plurality of solar light collecting devices 2 are provided, and the heat medium oil is heated by the plurality of solar light collecting devices 2. The sunlight concentrating device 2 may be a trough type, a tower type, a dish type, or the like.

  FIG. 3 is a diagram showing a flow of operation of the heat medium mixing unit 34 in the steam generation processing of the steam generator 1. In the heat medium mixing unit 34, during the steam generation process, the temperature sensor 342 in FIG. 1 repeatedly acquires the measured value of the temperature of the heat medium oil before heating at predetermined time intervals, and the operation in FIG. 3 is always performed. Hereinafter, the steam generation process in the steam generator 1 will be described while paying attention to the operation of the heat medium mixing unit 34.

  In the steam generation process, the heat medium oil is continuously fed from the heat medium tank 30 at a constant flow rate by driving the pump 32. Moreover, in the heat medium mixing part 34, it is confirmed at predetermined time intervals whether the temperature before heating (measured value) of the heat medium oil is lower than the set temperature. Here, the set temperature is the lowest temperature (for example, 200 ° C.) at which the steam generator 31 can generate the set pressure steam. The set temperature may be arbitrarily determined according to the use of steam generated in the steam generator 31.

  For example, immediately after the driving of the steam generator 1 is started at the same time as sunrise, the temperature before heating of the heat transfer oil is less than the set temperature (step S11). In this case, the first heat transfer oil is discharged by the flow rate adjustment valve 341. The flow rate is set to 0 (step S12). That is, all the heat medium oil fed from the heat medium tank 30 by the pump 32 flows through the bypass flow path 340. If the first flow rate is already 0, this state is maintained in step S12. The heat transfer oil that has passed through the bypass flow path 340 flows into the solar light collecting device 2 along the circulation path 33. Since the circulation path 33 is mainly formed by a heat insulating pipe, the heat transfer oil that has passed through the bypass flow path 340 flows into the solar light collecting device 2 with almost no drop in temperature.

  At this time, since the heat transfer oil is not supplied to the steam generator 31, the internal pressure (measured value) of the steam generator 31 is less than the set pressure. In the pressure adjustment unit 42, when the internal pressure is less than the set pressure, the pressure control valve 421 is closed, and no steam is supplied from the steam generator 31 to the external equipment 9. In the external facility 9, a necessary amount of steam is generated using the auxiliary boiler 91. As a result, the external equipment 9 can be operated while the steam supply flow rate from the steam generator 1 is zero. The steam supply path 41 is provided with a check valve, and the steam from the auxiliary boiler 91 does not flow back through the steam supply path 41.

  The temperature of the heat transfer oil circulating through the solar light collector 2 and the heat medium tank 30 using the bypass channel 340 gradually increases due to heating by the solar light collector 2. When the temperature before heating of the heat medium oil becomes equal to or higher than the set temperature (step S11), the heat medium mixing unit 34 adjusts the flow rate adjustment valve 341 so that the temperature before heating of the heat medium oil maintains the set temperature. Control is started (step S13). In the constant temperature control, the ratio of the first flow rate to the second flow rate is adjusted by the temperature sensor 342 while ensuring the supply of the heat transfer oil to the steam generator 31 by making the first flow rate of the heat transfer oil larger than 0. By changing based on the measured value, the temperature before heating of the heat transfer oil is kept approximately at the set temperature. For example, when the preheating temperature of the heat transfer oil is somewhat higher than the set temperature, the first flow rate is increased and the second flow rate is decreased. Further, when the temperature before heating of the heat transfer oil is lower to some extent than the set temperature, the second flow rate is increased and the first flow rate is reduced. When the constant temperature control is started, the constant temperature control is continued as long as the temperature before the heating of the heat transfer oil is lower than the set temperature does not continue for a predetermined continuous release time (the pressure described later) The same applies to the constant pressure control by the adjusting unit 42).

  In the steam generator 31, the heat transfer oil flows through the heat transfer tubes arranged inside, whereby the water stored inside is heated and steam is generated. In other words, the heat of the heat transfer oil is radiated in the steam generator 31. When the internal pressure of the steam generator 31 becomes equal to or higher than the set pressure, the pressure control valve 421 is slowly opened, and the opening degree of the pressure control valve 421 is adjusted so that the internal pressure is maintained at approximately the set pressure. That is, constant pressure control of the internal pressure by the pressure adjustment unit 42 is started. In the constant pressure control, the steam (saturated steam) in the steam generator 31 flows through the steam supply path 41 at a supply flow rate corresponding to the opening degree of the pressure control valve 421 and is supplied to the external equipment 9. In the external facility 9, the auxiliary boiler 91 is used to replenish the steam that is insufficient in the external facility 9.

  As the amount of solar radiation increases, the temperature of the heat transfer oil flowing into the heat transfer medium tank 30 from the solar light collecting device 2 gradually increases. In the heat medium mixing part 34, the first flow rate is increased and the second flow rate is decreased, thereby performing a constant temperature control of the pre-heating temperature of the heat medium oil. In the steam generator 31, the amount of steam generated (the amount generated per unit time) increases as the first flow rate increases, and the opening degree of the pressure control valve 421 and the steam supply flow rate to the external equipment 9 gradually increase. At this time, when a constant amount of steam is used in the external equipment 9, the amount of steam generated by the auxiliary boiler 91 is gradually reduced.

  In the steam generator 31 in the present embodiment, the temperature of the heat medium oil stored in the heat medium tank 30 is the highest temperature assumed (for example, 340 ° C. near the use upper limit of the heat medium oil, The second flow rate becomes 0 when the temperature is lower than the “maximum operating temperature”), for example, about 250 ° C. That is, all the heat medium oil fed from the heat medium tank 30 by the pump 32 is supplied to the steam generator 31. When the temperature of the heat medium oil stored in the heat medium tank 30 rises to the maximum use temperature, the amount of steam generated in the steam generator 31 (and the amount of water supplied from the water supply tank 51) becomes maximum. When the temperature of the heat transfer oil in the heat transfer medium tank 30 reaches the maximum use temperature, an amount of heat storage corresponding to the difference between the maximum use temperature and the set temperature (here, 140 ° C.) is substantially completed.

  For example, when sunlight is blocked by clouds or the like and the amount of solar radiation decreases, the temperature of the heat transfer oil flowing into the heat transfer medium tank 30 from the solar light collecting device 2 gradually decreases, and the heat stored in the heat transfer medium tank 30. The temperature of the medium oil also falls from the maximum operating temperature. When the temperature before heating of the heat transfer oil becomes (temporarily) lower than the set temperature, the first flow rate is reduced and the second flow rate is increased as constant temperature control. Even in a state where the amount of solar radiation is small, the temperature before heating of the heat medium oil is kept near the set temperature for a while by the high-temperature heat medium oil stored in the heat medium tank 30 (heat dissipation in the heat medium tank 30). Can be considered.) Further, the first flow rate does not become 0, and the supply of steam from the steam generator 31 to the external equipment 9 is continued. Of course, as the first flow rate decreases, the amount of steam generated by the steam generator 31 decreases, and the opening degree of the pressure control valve 421 and the steam supply flow rate to the external equipment 9 also gradually decrease. At this time, when a certain amount of steam is used in the external equipment 9, the amount of steam generated by the auxiliary boiler 91 is gradually increased.

  When the state where the amount of solar radiation is small becomes long, the temperature of the heat medium oil stored in the heat medium tank 30 gradually decreases to near the set temperature. Then, when the state in which the temperature before heating of the heat transfer oil is lower than the set temperature continues for the continuous release time (step S11), the first flow rate of the heat transfer oil is set to 0 (step S12). Further, even when the pressure control valve 421 is at the minimum opening degree, when the internal pressure of the steam generator 31 becomes less than the set pressure, the pressure control valve 421 is slowly closed and is in a closed state. Thereby, the supply flow rate of the steam from the steam generator 1 to the external facility 9 becomes zero.

  As described above, in the steam generator 1, the supply of steam can be continued for a certain period of time by storing heat in the heat medium tank 30 even when there is almost no amount of solar radiation. Therefore, by gradually increasing the output of the auxiliary boiler 91 during this period, it is possible to secure a necessary amount of steam in the external equipment 9 when the steam supply flow rate becomes zero. In the steam generator 1, when the amount of solar radiation disappears due to sunset, the driving of the pump 32 is stopped, and the steam generation process ends.

  FIG. 4 is a diagram showing a temperature change of the heat transfer oil during heat storage in the heat transfer tank 30 and shows a result obtained by a predetermined calculation. The vertical axis in FIG. 4 indicates the temperature of the heat medium oil in the heat medium tank 30, and the horizontal axis indicates time (the same applies in FIG. 5 described later). Here, the capacity of the heat medium tank 30 is 3000 liters, the initial temperature of the heat medium oil in the heat medium tank 30 is 200 ° C., and the heat medium oil at 340 ° C. is 2.78 liters per second from the solar light collector 2. The case where it flows in into the heat-medium tank 30 with the flow volume is shown. In the example of FIG. 4, the temperature of the heat transfer oil in the heat transfer tank 30 becomes about 330 ° C. in 50 minutes from the start of the flow of the heat transfer oil at 340 ° C., and the temperature of the heat transfer oil becomes about 340 ° C. in 90 minutes. . Actually, as the temperature of the heat medium oil in the heat medium tank 30 rises, the amount of steam generated in the steam generator 31 also increases.

  FIG. 5 is a diagram showing a temperature change of the heat medium oil during heat radiation in the heat medium tank 30, and shows a result obtained by calculation as in FIG. Here, the capacity of the heat medium tank 30 is 3000 liters, the initial temperature of the heat medium oil in the heat medium tank 30 is 340 ° C., and the heat medium oil at a set temperature of 200 ° C. is 2 from the solar light collector 2 per second. The case where it flows in into the heat medium tank 30 with the flow volume of .78 liter is shown. In the example of FIG. 5, the temperature of the heat medium oil in the heat medium tank 30 becomes about 215 ° C. in 40 minutes from the start of inflow of the heat medium oil at 200 ° C. As described above, when the temperature of the heat transfer oil supplied to the steam generator 31 is 200 ° C. or higher, the steam generator 31 can generate steam having a set pressure. Therefore, steam can be generated in the steam generator 31 while the temperature of the heat medium oil in the heat medium tank 30 is maintained at 200 ° C. or higher (for at least 40 minutes). As the temperature of the heat medium oil in the heat medium tank 30 decreases, the amount of steam generated in the steam generator 31 also decreases.

  As described above, in the steam generator 1, the branch position between the heat medium tank 30 and the steam generator 31 in the circulation path 33 and the merge between the steam generator 31 and the solar light collector 2. A bypass flow path 340 that connects the position 344 is provided. Then, the heat medium oil that has passed through the steam generator 31 is mixed with the heat medium oil that has passed through the bypass flow path 340 and sent to the solar light collector 2. Thereby, when the amount of solar radiation is large, the temperature of the heat transfer medium oil in the heat transfer medium tank 30 is raised in a short time while supplying the steam from the steam generator 31 to the external equipment 9, and is stored as sensible heat. Is possible. Further, even when the amount of solar radiation is small, the steam can be continuously supplied to the external equipment 9 for a certain period by using the high-temperature heat medium oil in the heat medium tank 30. As a result, in the steam generator 1, with a simple structure, a rapid change (mainly a decrease) in the steam supply flow rate due to a change in the amount of solar radiation is prevented, that is, the steam supply flow rate to the external equipment 9 is gently changed. Can be made.

  In the heat medium mixing unit 34, a flow rate adjusting valve 341 that is a flow rate adjusting unit is provided, and the temperature sensor 342 measures the temperature of the heat medium oil from the joining position 344 toward the solar light collecting device 2. Then, the first flow rate of the heat transfer oil flowing from the branch position to the steam generator 31 and the second flow rate of the heat transfer oil flowing through the bypass flow path 340 so that the measurement value of the temperature sensor 342 becomes the set temperature, It is adjusted by the flow rate adjustment valve 341. Thereby, when there is a sufficient amount of solar radiation, the first flow rate can be increased and steam can be supplied to the external equipment 9 at a relatively high supply flow rate while continuously storing heat in the heat medium tank 30. . Further, when the amount of solar radiation is small, by reducing the first flow rate (the supply flow rate of steam by the steam generator 31 is reduced), the period during which steam can be continuously supplied to the external equipment 9 is lengthened. be able to.

  FIG. 6 is a view showing a part of the steam generator 8 of the comparative example. In the steam generator 8 of the comparative example, the heat medium oil circulates through the solar light collector 81, the high temperature heat medium tank 82, the steam generator 83, and the low temperature heat medium tank 84 in order. Further, a three-way valve 85 is provided between the solar light collecting device 81 and the high-temperature heat medium tank 82, and the three-way valve 85 and the low-temperature heat medium tank 84 are connected by a bypass flow path 86. In the steam generator 8 of the comparative example, the heat transfer oil heated to 340 ° C. by the solar light collecting device 81 is stored in the high-temperature heat transfer medium tank 82, and the heat transfer oil at 340 ° C. is supplied to the steam generator 83. . The heat transfer oil radiated by the steam generator 83 is stored in the low-temperature heat transfer tank 84, and the heat transfer oil in the low-temperature transfer medium tank 84 is sent to the solar light collecting device 81 and heated by the sunlight concentration. The

  Here, in the steam generator 8 of the comparative example, when the temperature of the heat transfer oil that has passed through the solar light collector 81 is lower than 340 ° C. when the amount of solar radiation is small, the heat is passed through the bypass passage 86. The medium oil is returned to the low-temperature heat medium tank 84. Thereby, the temperature of the heat medium oil in the high temperature heat medium tank 82 is maintained in the vicinity of 340 ° C. The heat medium oil in the high temperature heat medium tank 82 is supplied to the steam generator 83 at a constant temperature and a constant flow rate. Accordingly, when the state of low solar radiation becomes longer, the heat transfer oil in the high-temperature heat transfer tank 82 disappears, and the generation of water vapor suddenly stops in the steam generator 83 (that is, the amount of generated steam suddenly reaches zero). descend.).

  On the other hand, in the steam generator 1, in a state where the amount of solar radiation is small, a part of the heat transfer oil flows through the bypass flow path 340, and the amount of heat consumed in the steam generator 31 is limited. The steam supply flow rate to 9 can be changed gradually. Further, in the steam generator 1, even when the temperature of the heat transfer oil that has passed through the solar light collector 2 is lower than the temperature of the heat transfer oil in the heat medium tank 30, The heat medium oil flows into the heat medium tank 30. In this manner, by allowing the temperature of the heat medium oil in the heat medium tank 30 to decrease (fluctuate), the low temperature heat medium tank 84 in the steam generator 8 of the comparative example can be omitted. Furthermore, since the heat medium tank 30 is the only tank for the heat medium in the circulation path 33, the amount of heat medium oil used is reduced as compared to the steam generator 8 of the comparative example, and the steam generator 1 The configuration can be simplified.

  By the way, although the external boiler 9 is provided with an auxiliary boiler 91 that generates steam with fuel, it is difficult for the auxiliary boiler 91 to change the amount of generated steam rapidly. However, in the steam generator 1, the steam supply flow rate to the external equipment 9 can be gradually changed as described above. Therefore, in the external equipment 9, a certain amount of steam is generated by the steam generator 1 and the auxiliary boiler 91. Can be used stably.

  The steam generator 1 can be variously modified.

  The flow rate adjusting unit may be realized by other than the flow rate adjusting valve 341 that is a three-way valve. For example, a combination of a two-way valve provided between the branch position and the steam generator 31 and a two-way valve provided in the bypass flow path 340 is provided as a flow rate adjustment unit, and the first flow rate and the second flow rate are It may be adjusted. Further, depending on the design of the steam generator 1, the flow rate adjustment unit may be omitted. For example, only the bypass channel 340 that connects the branch position between the heat medium tank 30 and the steam generator 31 in the circulation path 33 and the joining position 344 between the steam generator 31 and the solar light collector 2. Is provided as the heat medium mixing section 34. Also in this case, when the amount of solar radiation is large, the steam generator 31 generates steam, and the temperature of the heat transfer medium oil in the heat medium tank 30 can be raised in a short time to store heat, and the amount of solar radiation is small. Even in this case, the steam can be continuously supplied to the external equipment 9 for a certain period by using the high-temperature heat medium oil in the heat medium tank 30.

  A temperature sensor for measuring the temperature of the heat medium oil in the heat medium tank 30 may be provided, and the flow rate adjustment unit may be controlled based on the measured value of the temperature sensor. Further, in the circulation path 33, the flow rate adjustment unit may be controlled based on the measurement value of the temperature sensor 336 provided between the solar light collecting device 2 and the heat medium tank 30. In the heat medium mixing unit 34, the temperature sensor measures the temperature of the heat medium oil at any position in the circulation path 33, and controls the flow rate adjusting unit based on the measured value of the temperature sensor, whereby the first flow rate. It is possible to adjust the second flow rate appropriately.

  The heat medium stored in the heat medium tank 30 may be a molten salt in addition to the heat medium oil. In the above embodiment, water is stored in the steam generator 31, but other liquids such as ammonia may be stored in the steam generator 31, for example.

  The steam generator 1 using sunlight can be used for various purposes such as salt production and sake brewing in addition to seawater desalination (fresh water). The steam generator 1 can be added to various facilities having a boiler, and thereby the fuel consumed in the boiler (auxiliary boiler) can be reduced. Of course, the steam generator 1 may be used for power generation.

  The configurations in the above-described embodiments and modifications may be combined as appropriate as long as they do not contradict each other.

DESCRIPTION OF SYMBOLS 1 Steam generator 2 Sunlight condensing device 9 External equipment 30 Heat medium tank 31 Steam generator 32 Pump 33 Circulation path 34 Heat medium mixing part 91 Auxiliary boiler 340 Bypass flow path 341 Flow control valve 342 Temperature sensor 344 Merge position

Claims (6)

A steam generator using sunlight,
A solar concentrator that heats the heat medium with the concentrated sunlight;
A heat medium tank for storing the heat medium;
A vapor generator for storing a liquid and generating the vapor of the liquid by heating the liquid using the heat medium; and
A pump that continuously circulates the heat medium along a circulation path that returns from the heat medium tank to the heat medium tank via the steam generator and the solar light collecting device in order.
A bypass passage for connecting a branch position between the heating medium tank and the steam generator in the circulation path and a joining position between the steam generator and the solar light collecting device; A heating medium mixing section that mixes the heating medium that has passed through the steam generator with the heating medium that has passed through the bypass flow path and sends the mixing medium to the solar light collector;
A steam generator characterized by comprising: The steam generator according to claim 1,
The heating medium mixing part is
A temperature sensor for measuring the temperature of the heating medium in the circulation path;
A flow rate adjusting unit for adjusting a first flow rate of the heat medium flowing from the branch position to the steam generator and a second flow rate of the heat medium flowing through the bypass flow path based on a measurement value of the temperature sensor; ,
The steam generator characterized by further comprising. The steam generator according to claim 2,
The temperature sensor measures the temperature of the heating medium from the merging position toward the solar collector,
The steam generation apparatus, wherein the flow rate adjusting unit adjusts the first flow rate and the second flow rate so that a measurement value of the temperature sensor becomes a predetermined temperature. The steam generator according to any one of claims 1 to 3,
Even when the temperature of the heat medium that has passed through the solar light collector is lower than the temperature of the heat medium in the heat medium tank, the heat medium is transferred from the solar light collector to the heat medium tank. A steam generator characterized by flowing in. The steam generator according to any one of claims 1 to 4,
The steam generator according to claim 1, wherein the heat medium tank is the only tank for the heat medium in the circulation path. The steam generator according to any one of claims 1 to 5,
A steam generator according to claim 1, wherein an auxiliary boiler for generating steam by fuel is provided in an external facility to which the steam generated by the steam generator is supplied.

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