JP2016099099A - Drying system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use solar heat to suppress fuel consumption used for drying, suppress an increase in size of equipment and adjust the temperature of an object to be dried to a temperature suitable for drying in a drying system for drying fuel containing a lot of water, and the like.SOLUTION: The drying system includes: multiple solar heat collectors for heating a heat transfer medium with solar heat; and a drying furnace for drying the object to be dried by exchanging heat between the heat transfer medium heated by the solar heat collectors and the object to be dried.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a drying system.

  Conventionally, solid fuels such as lignite, biomass, and palm residue that contain a lot of moisture have been dried by sun drying or the like because they are poor in ignitability and combustibility due to the influence of contained moisture. However, the sun drying requires a wide space for placing the fuel and it is difficult to control the temperature of the fuel during drying. For this reason, in addition to heating by solar radiation, contact with air causes oxidation and deterioration, and heat generation from oxidation is added to the heat of solar radiation, which may lead to abnormal temperature rise and spontaneous ignition.

  On the other hand, it is conceivable to artificially create hot air and dry the fuel using this hot air. However, it is necessary to consume a large amount of fuel to generate such hot air, and a large amount of carbon dioxide. Discharge. For this reason, for example, by applying the gasification facility shown in Patent Document 1 and heating the fuel with heat obtained by collecting sunlight, it is possible to perform drying without consuming the fuel. .

JP 2001-123183 A

  However, in the gasification facility disclosed in Patent Document 1, the fuel is heated to nearly 1000 ° C. because the concentrated sunlight is directly irradiated onto the fuel. Such a temperature is not a problem as long as it is a gasification facility for gasifying fuel, but is too high to dry the fuel.

  Further, in the gasification facility disclosed in Patent Document 1, in order to heat the fuel to near 1000 ° C., the sunlight collected by a plurality of heliostats is collected on a reflection mirror supported upward by a large tower. Furthermore, the light is guided to the gasification furnace. For this reason, a large number of heliostats, large towers, and the like are required, and the facilities are enlarged. In addition, since sunlight collected from a large number of heliostats installed in a wide range is concentrated in a limited range, there is a problem that complicated control is required and equipment costs increase. In the drying system for drying the fuel, it is not necessary to heat the temperature of the fuel to near 1000 ° C. Therefore, it is not necessary to install a large facility as shown in Patent Document 1, and it is desirable to downsize the facility.

  The present invention has been made in view of the above-described problems, and in a drying system for drying an object to be dried, the consumption of fuel used for drying is suppressed by using solar heat, and the size of equipment is increased. The object is to suppress and to adjust the temperature of the material to be dried to a temperature suitable for drying.

  The present invention adopts the following configuration as means for solving the above-described problems.

  The first invention is a drying system, which heats a heat transfer medium by solar heat and heats the solar heat collector provided by a plurality, the heat transfer medium heated by the solar heat collector, and an object to be dried. A configuration is adopted in which a drying furnace for drying the material to be dried is provided by replacement.

  According to a second invention, in the first invention, the heat transfer medium which is disposed between the solar collector and the drying furnace and is vaporized by being heated by the solar collector is temporarily stored. A configuration is adopted in which a steam drum is provided to store automatically.

  According to a third invention, in the first or second invention, a configuration is provided in which a superheater that further raises the temperature of the heat transfer medium heated by the solar collector is provided.

  According to a fourth invention, in any one of the first to third inventions, fluidized gas supply means for fluidizing the material to be dried in the drying furnace by supplying fluidized gas to the drying furnace. Adopt the configuration.

  According to a fifth invention, in the fourth invention, the fluidized gas supply means includes a superheated steam supply unit that supplies superheated steam as the fluidized gas to the drying furnace.

  A sixth invention adopts a configuration in which, in the fourth or fifth invention, an inert gas supply unit that supplies an inert gas as the fluidized gas to the drying furnace as the fluidized gas supply means is employed. To do.

  7th invention employ | adopts the structure provided with the auxiliary boiler which heats the said heat transfer medium separately from the said solar collector in either of the said 1st-6th invention.

  An eighth invention adopts a configuration in which, in the seventh invention, a control device is provided that operates the auxiliary boiler in accordance with at least one of a sunrise time and a sunset time.

  According to this invention, the structure provided with two or more solar collectors which heat a heat transfer medium is employ | adopted. Therefore, by installing as many solar collectors as possible to collect the energy necessary to dry the object to be dried, the object to be dried can be dried, and a huge tower or reflection mirror is installed. It is possible to perform drying using solar heat without doing so. In addition, in comparison with the amount of heat required for gasifying solid fuel such as coal, the amount of heat required for drying can be reduced. Therefore, in the present invention, a large number of heliostats are used as in the gasification facility described above. Not only does it need to be installed, it also does not require a complex control system that focuses light from a widely installed heliostat to a limited area. Therefore, according to this invention, the enlargement of an installation and the complexity of a control system can be suppressed. Furthermore, according to the present invention, the object to be dried is not directly heated by the solar heat collected by the solar collector, but the heat transfer medium is heated by the solar heat, and the object to be dried is heated by the heat transfer medium. The configuration is adopted. For this reason, the temperature of a to-be-dried object can be easily adjusted by adjusting the physical property (for example, saturated steam temperature) of a heat transfer medium, the flow velocity of the heat transfer medium at the time of heat exchange, etc. Therefore, according to this invention, it becomes possible to adjust the temperature of a to-be-dried object to the temperature suitable for drying.

It is a flowchart which shows schematic structure of the drying system in 1st Embodiment of this invention. It is a schematic diagram which shows schematic structure of the solar collector with which the drying system in 1st Embodiment of this invention is provided. In the drying system in 1st Embodiment of this invention, it is explanatory drawing in the case of operating an auxiliary boiler only before and after the sunrise time. In the drying system in a 1st embodiment of the present invention, it is an explanatory view in the case of making an auxiliary boiler operate only before and after sunset time. In the drying system in 1st Embodiment of this invention, it is explanatory drawing in the case of making an auxiliary boiler drive before and after sunrise time, and before and after sunset time. It is a flowchart which shows schematic structure of the drying system in 2nd Embodiment of this invention. In the drying system in 2nd Embodiment of this invention, it is explanatory drawing in the case of operating an auxiliary boiler only before and after the sunrise time. In the drying system in 2nd Embodiment of this invention, it is explanatory drawing in the case of making an auxiliary boiler drive only before and after sunset time. In the drying system in 2nd Embodiment of this invention, it is explanatory drawing in the case of driving an auxiliary boiler before and after sunrise time, and before and after sunset time. It is a flowchart which shows schematic structure of the drying system in 3rd Embodiment of this invention.

  Hereinafter, an embodiment of a drying system according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size.

(First embodiment)
FIG. 1 is a flowchart showing a schematic configuration of a drying system 1 of the present embodiment. As shown in this figure, the drying system 1 of this embodiment includes a plurality of solar collectors 2, a steam drum 3, an auxiliary boiler 4, a drying furnace 5, and a fluidizing gas supply device 6 (fluidizing gas). Supply means, inert gas supply unit), heat transfer medium circulation unit 7, and control device 8.

  FIG. 2 is a schematic diagram illustrating a schematic configuration of the solar heat collector 2, where (a) is a perspective view and (b) is a cross-sectional view. As shown in these drawings, the solar collector 2 includes a first reflecting plate 2a, a second reflecting plate 2b, a heat transfer tube 2c, and a driving device 2d.

  The first reflecting plate 2a is a substantially semi-cylindrical reflecting plate whose inner surface serving as a reflecting surface is directed upward, and reflects sunlight so as to be condensed on the second reflecting plate 2b. The second reflecting plate 2b is a substantially semi-cylindrical reflecting plate supported by a support portion 2e fixed to the first reflecting plate 2a, and an inner surface serving as a reflecting surface is directed to the first reflecting plate 2b. The heat transfer tube 2c is a straight pipe disposed at the condensing position of the second reflecting plate 2b, and the heat transfer medium X flows through the heat transfer tube 2c. The heat transfer tube 2c is fixed by a support mechanism provided outside so as to pass through a through hole provided in the support portion 2e. The driving device 2d supports the first reflecting plate 2a and the second reflecting plate 2b so as to be movable around the heat transfer tube 2c. For example, under the control of the control device 8, the reflecting surface of the first reflecting plate 2a is exposed to the sun. The 1st reflecting plate 2a and the 2nd reflecting plate 2b are moved so that it may face. The second reflector 2b improves the light collection efficiency, and also heats the outer surface of the heat transfer tube 2c on the back side when viewed from the first reflector 2a, thereby obtaining the effect of improving heat collection. It can be omitted.

  In the solar heat collector 2, sunlight reflected by the first reflecting plate 2a and the second reflecting plate 2b is collected in the heat transfer tube 2c, and the heat transfer medium X inside the heat transfer tube 2c is obtained by the solar heat obtained thereby. Heated. In the present embodiment, water is used as the heat transfer medium X, and the heat transfer medium X heated in the solar heat collector 2 is heated to such an extent that a part or the whole is vaporized. The heat transfer medium X is not limited to water, and for example, an organic solvent, an inorganic salt, or a metal can be used. For example, when an organic solvent is used, alcohols, oils and fats having a relatively high boiling point, and liquid at room temperature can be used. When inorganic salts or metals are used, those that become liquid at a relatively low temperature are selected in order to ensure fluidity.

  As shown in FIG. 1, a plurality of solar collectors 2 that heat the heat transfer medium X by such solar heat are provided, and each is connected to the steam drum 3 via the collecting pipe 2f. The number of solar collectors 2 installed is determined based on the amount of steam required to dry the material to be dried Y in the drying furnace 5. For example, the number of installed solar collectors 2 is determined so that the amount of steam generated by the solar collector 2 in operation exceeds the amount of steam required by the drying furnace 5 during daylight hours. .

  The steam drum 3 is a container for temporarily storing the heat transfer medium X partially or wholly vaporized by being heated by the solar heat collector 2, and the solar heat collector 2 and the drying furnace 5. It is arranged between. Further, the upper part of the steam drum 3 is connected to the drying furnace 5, and the bottom part is connected to the heat transfer medium circulation part 7. When the heat transfer medium X is supplied to the steam drum 3, the heat transfer medium X in a vapor state is accumulated on the upper portion of the steam drum 3 and is sent out toward the drying furnace 5. Further, the heat transfer medium X in a liquid state is accumulated at the bottom of the steam drum 3 and is sent out to the heat transfer medium circulation unit 7.

  The auxiliary boiler 4 is a general-purpose boiler that can be easily started and stopped, for example, and is connected to the steam drum 3. The auxiliary boiler 4 supplementarily heats the heat transfer medium X to generate steam when the amount of steam generated in the solar collector 2 decreases near sunrise time or sunset time. Supply to the steam drum 3. In the present embodiment, the auxiliary boiler 4 is connected to the control device 8, and generates steam under the control of the control device 8.

  The drying furnace 5 includes a chamber 5a, a dividing wall 5b that divides the interior of the chamber 5a into a plurality of regions in the horizontal direction, and a heat transfer tube 5c that is inserted into the chamber 5a. The chamber 5a is a container in which the material to be dried Y is stored. In the chamber 5a, when the material to be dried Y is supplied from the outside, a part of the material to be dried Y previously stored is pushed out and discharged. A plurality of dividing walls 5b are provided at the bottom of the chamber 5a, and a plurality of dividing walls 5b are provided so that the wall surfaces face each other. As this dividing wall 5b, there are provided a first dividing wall 5b1 having an opening in the lower part and a second dividing wall 5b2 having no opening and lower in height than the first dividing wall 5b1. They are alternately arranged in the chamber 5a. As the interior of the chamber 5a is divided by the plurality of dividing walls 5b, the material to be dried Y advances while meandering up and down in the chamber 5a as shown by the arrows in FIG. The heat transfer tube 5 c has an inlet end connected to the steam drum 3 and an outlet end connected to the heat transfer medium circulating unit 7. A heat transfer medium X that exchanges heat with the material to be dried Y in the chamber 5a flows through the heat transfer tube 5c. In the drying furnace 5, the material to be dried Y is exchanged by heat exchange between the material to be dried Y that flows by the fluidizing gas Z supplied from the fluidizing gas supply device 6 and the heat transfer medium X that flows through the heat transfer pipe 5 c. dry.

  The to-be-dried material Y dried by such a drying furnace 5 is a solid fuel used as fuel, such as a pulverized coal boiler (not shown), and contains a lot of moisture (for example, a moisture content of 20% or more). Examples of such a material to be dried Y include powdered lignite and biomass. In addition, in order to improve the fluidity | liquidity in the chamber 5a, you may store fluid media, such as sand other than such to-be-dried material Y, in the inside of the chamber 5a. This fluid medium is discharged from the chamber 5a, separated from the material to be dried Y, and returned to the chamber 5a again.

  The fluidizing gas supply device 6 includes a circulation pipe 6a, an inert gas generator 6b, a blower 6c, a heat exchanger 6d, and a cooler 6e. The circulation pipe 6a is a pipe whose one end is branched into a large number and connected to the bottom of the chamber 5a, and the other end is connected to the ceiling of the chamber 5a. The one end side of the circulation pipe 6a is connected to the bottom of the chamber 5a so that each branch end is connected to each region of the chamber 5a divided by the dividing wall 5b. The inert gas generator 6b generates, for example, nitrogen gas (inert gas) used as a fluid gas from the atmosphere, and is connected to the circulation pipe 6a. The blower 6c is provided in the middle part of the circulation piping 6a, and pumps the fluidized gas Z. The blower 6c pumps the fluidizing gas Z toward one end of the circulation pipe 6a (side connected to the bottom of the chamber 5a) so that the fluidizing gas Z is supplied upward from the bottom of the chamber 5a. To do. Thereby, the fluidizing gas Z is supplied into the chamber 5a from one end side (the side connected to the bottom of the chamber 5a) of the circulation pipe 6a, and connected to the other end side (the ceiling part of the chamber 5a) of the circulation pipe 6a. The fluidized gas Z inside the chamber 5a is recovered from the side).

  6 d of heat exchangers are the intermediate parts of the circulation piping 6a, and are arrange | positioned in the downstream of the blower 6c. The heat exchanger 6d exchanges heat between a heat transfer medium X flowing through a return pipe 7a (described later) included in the heat transfer medium circulation unit 7 and a fluidized gas Z flowing through the circulation pipe 6a. In this heat exchanger 6d, the heat transfer medium X and the fluidized gas Z are heat-exchanged to heat the fluidized gas Z before being supplied to the drying furnace 5, and the fluidized gas Z causes the chamber 5a to be heated. It is possible to prevent the internal temperature from decreasing.

  The cooler 6e is an intermediate part of the circulation pipe 6a and is arranged on the upstream side of the blower 6c. The cooler 6e cools the fluidizing gas Z in order to condense and separate moisture contained in the fluidizing gas Z heated by passing through the inside of the chamber 5a. Thus, the dried fluidized gas Z is supplied to the blower 6c and the like, and it is possible to prevent dew condensation from occurring in the blower 6c and the like.

  The fluidized gas Z is supplied upward from the bottom of the chamber 5a by the fluidized gas supply device 6 as described above, whereby the material to be dried Y stored in the chamber 5a is fluidized. Thereby, heat exchange between the material to be dried Y and the heat transfer medium X is promoted, and the material to be dried Y can be dried in a short time.

  The heat transfer medium circulation unit 7 includes a return pipe 7a, a condenser 7b, a feed water pump 7c, a feed water preheater 7d, and a steam drum connection pipe 7e. The return pipe 7 a is a pipe that connects the drying furnace 5 and the solar collector 2 and returns the heat transfer medium X discharged from the drying furnace 5 to the solar collector 2 again. As shown in FIG. 1, the return pipe 7a passes through a heat exchanger 6d, whereby heat transfer medium X flowing through the return pipe 7a and fluidized gas Z flowing through the circulation pipe 6a are heated. The amount of heat of the heat transfer medium X is transferred to the fluidizing gas Z.

  The condenser 7b is disposed in the middle of the return pipe 7a and downstream of the heat exchanger 6d, and cools and liquefies the heat transfer medium X, which is steam, by, for example, heat exchange with the atmosphere. The feed water pump 7 c is arranged further downstream of the condenser 7 b and pumps the heat transfer medium X liquefied by the condenser 7 b toward the solar collector 2. The feed water preheater 7d is arranged further downstream of the feed water pump 7c, and exchanges heat between the heat transfer medium X discharged from the feed water pump 7c and the heat transfer medium X upstream of the condenser 7b. The heat transfer medium X supplied to the solar collector 2 is preheated. The steam drum connection pipe 7e is a pipe connecting the bottom of the steam drum 3 and the return flow pipe 7a, and condensates the liquid heat transfer medium X collected at the bottom of the steam drum 3 without passing through the drying furnace 5. Guide to the upstream side of the vessel 7b. A port (not shown) for additionally supplying the heat transfer medium X to the return pipe 7a is provided on the upstream side of the water supply pump 7c. Then, the heat transfer medium X is additionally supplied from the port to the return pipe 7a.

  The control device 8 controls the entire drying system 1 of the present embodiment, and controls, for example, the auxiliary boiler 4, the inert gas generator 6b, the blower 6c, and the feed water pump 7c. In the drying system 1 of the present embodiment, the operation period of the auxiliary boiler 4 is determined under such control of the control device 8. For example, under the control of the control device 8, the auxiliary boiler 4 is operated only before and after the sunrise time, is operated only before and after the sunset time, or is operated before and after the sunrise time and before and after the sunset time. Although omitted in FIG. 1, in the drying system 1 of the present embodiment, a valve is provided at an appropriate position. The flow rates of the heat transfer medium X and the fluidized gas Z are adjusted by adjusting the opening degree of these valves by the control of the control device 8 or the like.

  Then, operation | movement of the drying system 1 of this embodiment comprised in this way is demonstrated. In the following description of the operation, it is assumed that the material to be dried Y is continuously supplied to the chamber 5a of the drying furnace 5 in a constant amount.

  When sunlight is collected by the first reflector 2a and the second reflector 2b of the solar collector 2 and the heat transfer medium X flowing through the heat transfer tube 5c is heated by solar heat, a part of the heat transfer medium X is vaporized. And the heat transfer medium X in a gas-liquid mixed state is generated. The heat transfer medium X generated by the plurality of solar collectors 2 is collected by the collecting pipe 2 f and supplied to the steam drum 3. The heat transfer medium X is gas-liquid separated in the steam drum 3, and the steam heat transfer medium X is supplied to the heat transfer tube 5 c of the drying furnace 5. On the other hand, the liquid heat transfer medium X is supplied from the steam drum connection pipe 7 e to the heat transfer medium circulation unit 7 and supplied again to the solar heat collector 2.

  In the fluidizing gas supply device 6, fluidizing gas Z (inert gas) is supplied from the inert gas generator 6b to the circulation pipe 6a, and the blower 6c is driven to fluidize the circulation pipe 6a. The gas Z is pumped toward the drying furnace 5. The fluidizing gas Z supplied to the drying furnace 5 is heated in advance in the heat exchanger 6d and then supplied from the bottom of the chamber 5a to the inside of the chamber 5a. By supplying the fluidizing gas Z from the bottom of the chamber 5a, the material to be dried Y in the chamber 5a is fluidized. The fluidized gas Z in the chamber 5a is recovered from the upper part of the chamber 5a to the circulation pipe 6a, and after moisture is removed in the cooler 6e, it is pumped again by the blower 6c.

  When the heat transfer medium X supplied to the heat transfer tube 5c inserted into the chamber 5a as described above is supplied, the heat transfer medium X inside the heat transfer tube 5c and the material to be dried Y outside the heat transfer tube 5c, The material to be dried Y is heated by heat exchange. As a result, the moisture contained in the material to be dried Y evaporates and the material to be dried Y is dried. The dried to-be-dried material Y is discharged to the outside of the chamber 5a by being continuously pushed by the new to-be-dried material Y supplied to the chamber 5a. In addition, the water | moisture content evaporated from the to-be-dried substance Y is collect | recovered by the circulation piping 6a with the fluidization gas Z.

  The heat transfer medium X passing through the heat transfer tube 5 c and discharged to the outside of the chamber 5 a flows into the return pipe 7 a of the heat transfer medium circulation unit 7. The heat transfer medium X flowing into the return pipe 7a passes through the heat exchanger 6d, passes through the feed water preheater 7d, and is returned to the liquid by being cooled by the condenser 7b. The heat transfer medium X that has become liquid is pumped toward the solar heat collector 2 by the water supply pump 7c. The heat transfer medium X pumped by the feed water pump 7c is preheated in the feed water preheater 7d and then supplied to the solar heat collector 2 again.

  The auxiliary boiler 4 is operated only before and after the sunrise time, only before and after the sunset time, or before and after the sunrise time and before and after the sunset time. When the auxiliary boiler 4 is operated, steam (heat transfer medium X) is generated and supplied to the steam drum 3. Thus, the steam supplied from the auxiliary boiler 4 to the steam drum 3 is used by being mixed with the steam (heat transfer medium X) supplied from the solar heat collector 2 to the steam drum 3.

  Then, the example of the driving | operation pattern which uses the auxiliary boiler 4 of the drying system 1 of this embodiment is demonstrated with reference to FIGS.

  FIG. 3 is an explanatory diagram when the auxiliary boiler 4 is operated only before and after the sunrise time in the drying system 1 of the present embodiment. Moreover, FIG. 4 is explanatory drawing in the case of making the auxiliary boiler 4 drive only before and after sunset time in the drying system 1 of this embodiment. FIG. 5 is an explanatory diagram when the auxiliary boiler 4 is operated before and after the sunrise time and before and after the sunset time in the drying system 1 of the present embodiment. In these figures, a graph showing the relationship between the time and the temperature of the heat transfer medium X in the steam drum 3 is shown at the top, but this graph shows the relationship between the time and the energy obtained from the sun for reference. The graphs shown are superimposed.

  As shown in FIG. 3, when the auxiliary boiler 4 is operated before and after the sunrise time, the operation of the auxiliary boiler 4 is started before sunrise. Since the heat transfer medium X cannot be heated by the solar collector 2 at the time before sunrise, even if the steam is supplementarily supplied from the auxiliary boiler 4 to the steam drum 3, the solar collector 2 side The temperature of the heat transfer medium X supplied to the steam drum 3 through the collecting pipe 2f is low, and the temperature of the heat transfer medium X in the entire steam drum 3 does not reach the boiling point.

  Note that the drying system 1 of the present embodiment performs a preheating operation until the temperature of the heat transfer medium X in the steam drum 3 reaches the boiling point. This preheating operation is an operation performed without supplying the material to be dried Y to the drying furnace 5, and is an operation for gradually raising the temperature of the heat transfer medium X toward the boiling point. The preheating operation is performed in a state where the drying object Y is not stored in the drying furnace 5 or in a state where the drying object Y which has not been dried in the previous day is stored in the drying furnace 5. In such preheating operation, the heat transfer medium X is gradually heated by the operation of the auxiliary boiler 4 (including heating by the solar heat collector 2 after sunrise). In the preheating operation, the fluidizing gas supply device 6 supplies the fluidizing gas Z to the drying furnace 5. Thereby, the fluidizing gas Z is also heated with the temperature increase of the heat transfer medium X, and it is possible to prevent the material to be dried Y from being cooled by the fluidizing gas Z after the start of the drying operation.

  At the sunrise time, although the energy obtained from the sun is lower than after noon, the heat transfer medium X is heated by the solar collector 2, and the temperature of the heat transfer medium X in the steam drum 3 rapidly rises to the boiling point. . When the temperature of the heat transfer medium X in the steam drum 3 reaches the boiling point, the auxiliary boiler 4 is stopped, the material to be dried Y is put into the drying furnace 5, and the drying operation for drying the material to be dried Y is performed. When the sunset time approaches and the energy obtained from the sun decreases, the temperature of the heat transfer medium X falls below the boiling point. At this point, the supply of the material to be dried Y to the drying furnace is stopped and the drying operation is stopped. To do.

  Thereafter, the cooling operation is performed until the sunset time. In this cooling operation, for example, the solar heat collector 2 is directed in a direction different from the sun, so that the heat transfer medium X is not heated by the solar heat collector 2 and the fluidizing gas supply device 6 supplies the drying furnace 5 to the drying furnace 5. The supply of fluidizing gas Z is continued. As a result, the material to be dried Y is stirred without being heated, and the temperature inside the drying furnace 5 is rapidly lowered. Then, after the temperature inside the drying furnace 5 is cooled to a temperature at which there is no risk of spontaneous ignition or the like, the cooling operation is terminated, and the drying system 1 of the present embodiment is stopped until the operation is resumed the next day.

  When the auxiliary boiler 4 is not operated before and after the sunrise time, the heat transfer medium X is heated by the solar heat collector 2 after sunrise, and therefore, in the steam drum 3 as shown by a one-dot chain line in FIG. The time when the heat transfer medium X reaches the boiling point is delayed. Therefore, by operating the auxiliary boiler 4 before and after the sunrise time, the start timing of the dry operation possible period can be advanced, and the to-be-dried object Y can be dried in a longer period.

  Moreover, as shown in FIG. 4, when driving the auxiliary boiler 4 before and after the sunset time, the operation of the auxiliary boiler 4 is started before sunset. As the sun approaches, the energy obtained from the sun decreases, so the energy for heating the heat transfer medium X in the solar collector 2 decreases, and the temperature of the heat transfer medium X is maintained at the boiling point only by the solar collector 2. Can not do. However, the temperature of the heat transfer medium X does not immediately decrease to room temperature even when sunset approaches and further passes the sunset time, but gradually decreases (see FIG. 3). Here, as shown in FIG. 4, when the auxiliary boiler 4 is operated before and after the sunset time, new steam is supplied from the auxiliary boiler 4 to the steam drum 3, so that before and after the sunset time. And the fall of the temperature of the heat transfer medium X can be suppressed. For this reason, the temperature of the heat transfer medium X can be maintained at the boiling point for a while even after the sunset time has passed, and the drying of the material to be dried Y can be continued. In this way, by operating the auxiliary boiler 4 before and after the sunset time, it becomes possible to extend the drying operation possible period until after the sunset time as shown in FIG. Can be dried.

  Further, as described above, the temperature of the heat transfer medium X cannot be maintained at the boiling point only by the solar collector 2 before and after the sunset time, but the heat transfer medium X is warmed by daytime operation. Yes. For this reason, the input energy for maintaining the temperature of the heat transfer medium X at the boiling point using the auxiliary boiler 4 is less than that when the auxiliary boiler 4 is operated before and after sunrise. Therefore, when the auxiliary boiler 4 is operated before and after the sunset time, it is possible to extend the drying operation possible period with less fuel than when the auxiliary boiler 4 is operated before and after sunrise.

  Further, as shown in FIG. 5, when the auxiliary boiler 4 is operated before and after the sunrise time and before and after the sunset time, the start timing of the dry operation possible period is advanced, and further the dry operation available period is set to the sunset time. It becomes possible to extend until after the time. In such a case, more fuel is required than when the auxiliary boiler 4 is operated only before and after the sunrise time, and when the auxiliary boiler 4 is operated only before and after the sunset time. A dry operation possible period can be secured. For this reason, for example, this operation pattern is useful when the operation time of the factory where the drying system 1 of the present embodiment is installed is long and it is desired to operate the drying system 1 for a long time according to the operation time.

  According to the drying system 1 of this embodiment as described above, a configuration including a plurality of solar collectors 2 that heat the heat transfer medium X is employed. For this reason, it is possible to dry the material to be dried Y by installing as many solar collectors as necessary to collect the energy necessary for drying the material to be dried Y. It is possible to perform drying using solar heat without installing. In addition, since the amount of heat required for drying is less than the amount of heat necessary for gasifying solid fuel such as coal, the drying system 1 of the present embodiment has a large number of gasification facilities. Not only does he need to install a heliostat, it also does not require a complex control system that focuses light from a widely installed heliostat to a limited area. Therefore, according to the drying system 1 of this embodiment, the enlargement of an installation and the complexity of a control system can be suppressed.

  Furthermore, according to the drying system 1 of the present embodiment, the object to be dried Y is not directly heated by the solar heat collected by the solar heat collector 2, but the heat transfer medium X is heated by solar heat, and the heat transfer medium The structure which heats the to-be-dried object Y by X is employ | adopted. For this reason, the temperature of the to-be-dried object Y can be easily adjusted by adjusting the physical property (for example, saturation steam temperature) of the heat transfer medium X, the flow velocity of the heat transfer medium X at the time of heat exchange, etc. For example, in the drying system 1 of this embodiment, since water is used as the heat transfer medium X, it is possible to prevent the temperature of the material to be dried Y from becoming equal to or higher than the water saturation temperature. In addition, piping etc. through which the heat transfer medium X flows are closed spaces, and the pressure in the space is increased when the heat transfer medium X is vaporized. For this reason, in the drying system 1 of this embodiment, the saturation temperature of the heat transfer medium X is, for example, about 160 ° C. to 170 ° C.

  Therefore, according to the drying system 1 of the present embodiment as described above, the consumption of fuel used for drying can be suppressed by utilizing solar heat, and the increase in size of the facility can be suppressed. Furthermore, the temperature of the material to be dried Y can be adjusted to a temperature suitable for drying.

  In the drying system 1 of the present embodiment, the heat transfer medium X that is disposed between the solar collector 2 and the drying furnace 5 and is vaporized by being heated by the solar collector 2 is temporarily used. A steam drum 3 is provided for storage. For this reason, for example, even if there is a variation in the heating performance in each solar collector 2 due to the arrangement and individual differences and there is a difference in the ability to generate steam, all the steam is collected once in the steam drum 3, Since the steam drum 3 is supplied to the drying furnace 5, the heat transfer medium X can always be stably supplied to the drying furnace 5. Further, when a certain amount of steam accumulates inside the steam drum 3, for example, even when the sun is temporarily hidden behind clouds and steam cannot be generated sufficiently by the solar collector 2, The supply of steam can be continued.

  Moreover, in the drying system 1 of this embodiment, the to-be-dried substance Y flows in the chamber 5a by supplying the fluidizing gas Z from the fluidizing gas supply device 6 into the chamber 5a. For this reason, heat exchange between the material to be dried Y and the heat transfer medium X is promoted, and the material to be dried Y can be dried in a shorter time. Further, the fluidizing gas supply device 6 supplies the inert gas as the fluidizing gas Z to the drying furnace 5. For this reason, oxygen does not enter the chamber 5a of the drying furnace 5, and it is possible to prevent the material to be dried Y from burning in the drying furnace 5 by any chance.

  Further, the drying system 1 of the present embodiment includes an auxiliary boiler 4 that heats the heat transfer medium X separately from the solar collector 2. For this reason, when the steam required by the drying furnace 5 cannot be generated in the solar collector 2, the material to be dried Y can be dried by generating the steam with the auxiliary boiler 4. For example, by operating the auxiliary boiler 4 before and after the sunrise time and before and after the sunset time, it is possible to extend the drying operation possible period (the period during which the material to be dried Y can be dried) as described above. It becomes.

  Moreover, in the drying system 1 of this embodiment, the control apparatus 8 operates the auxiliary boiler 4 according to at least one of sunrise time and sunset time. Therefore, as described above with reference to FIGS. 4 to 6, it is possible to ensure a longer drying operation possible period as compared with the case where the auxiliary boiler 4 is not used.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. In the description of the present embodiment, the description of the same parts as those of the first embodiment is omitted or simplified.

  FIG. 6 is a flowchart showing a schematic configuration of the drying system 1A of the present embodiment. As shown in this figure, the drying system 1A of the present embodiment is different from the drying system 1 of the first embodiment in the solar superheater 10 (superheater) and the fluidized steam supply unit 11 (fluidized gas supply). Means, a superheated steam supply unit).

  The solar superheater 10 is disposed between the steam drum 3 and the drying furnace 5. This solar superheater 10 has the same configuration as that of the solar heat collector 2, and the heat transfer medium X supplied from the steam drum 3 to the heat transfer pipe 5 c of the drying furnace 5 is heated to a saturation temperature or higher (for example, 200). Temperature). In addition, in 1 A of drying systems of this embodiment, although the structure with which only one solar superheater 10 is provided is employ | adopted, the structure provided with the several solar superheater 10 is also employable.

  The fluidized steam supply unit 11 includes a superheated steam supply pipe 11a and an opening / closing valve 11b. The superheated steam supply pipe 11a is a pipe connecting the solar superheater 10 and the bottom of the chamber 5a, and supplies the heat transfer medium X heated by the solar superheater 10 into the chamber 5a as a fluidizing gas. The on-off valve 11b is disposed in the middle of the superheated steam supply pipe 11a, and opens and closes a flow path formed by the superheated steam supply pipe 11a. The on-off valve 11b is controlled by the control device 8, for example.

  In the drying system 1A of the present embodiment having such a configuration, the heat transfer medium X of the steam discharged from the steam drum 3 is heated by the solar superheater 10 to a temperature equal to or higher than the saturation temperature, and then transferred to the drying furnace 5. It is supplied to the heat pipe 5c. Therefore, the heat transfer medium X having a higher temperature than that of the drying system 1 of the first embodiment is supplied to the heat transfer tube 5 c of the drying furnace 5. Therefore, the drying temperature in the drying furnace 5 can be further increased, and the material to be dried Y can be dried in a short time.

  Further, in the drying system 1A of the present embodiment, the control device 8 opens the opening / closing valve 11b as necessary during the period in which the heat transfer medium X is overheated by the solar superheater 10. By opening the on-off valve 11b in this way, the heat transfer medium X is supplied as fluidized gas into the chamber 5a through the superheated steam supply pipe 11a. For example, when the temperature in the chamber 5a is low, such as when the drying system 1A starts operating, when the heat transfer medium X is directly touched to the object to be dried Y, the heat transfer medium X is condensed and the surface of the object to be dried Y Becomes wet and inhibits the flow of the material to be dried Y. For this reason, when the temperature in the chamber 5a is low, the fluidizing gas Z made of an inert gas is supplied to the chamber 5a by the fluidizing gas supply device 6 as in the drying system 1 of the first embodiment.

  Next, examples of operation patterns in the drying system 1A of the present embodiment will be described with reference to FIGS.

  FIG. 7 is an explanatory diagram when the auxiliary boiler 4 is operated only before and after the sunrise time in the drying system 1A of the present embodiment. FIG. 8 is an explanatory diagram when the auxiliary boiler 4 is operated only before and after the sunset time in the drying system 1A of the present embodiment. FIG. 9 is an explanatory diagram when the auxiliary boiler 4 is operated before and after the sunrise time and before and after the sunset time in the drying system 1A of the present embodiment.

  As shown in FIG. 7, when the auxiliary boiler 4 is operated before and after the sunrise time, the operation of the auxiliary boiler 4 is started before sunrise. At the start of operation, a preheating operation is performed as in the drying system 1 of the first embodiment. However, during this time, the temperature of the heat transfer medium X does not reach the boiling point, and the heat transfer medium X (superheated steam) heated in the solar superheater 10 is not generated. The fluidizing gas Z made of

  When the sunrise time passes and the temperature of the heat transfer medium X reaches the boiling point, a new material to be dried Y is supplied to the chamber 5a and the drying operation is started. Further, when the heat transfer medium X heated by the solar superheater 10 is generated, the supply of the inert gas chamber 5a by the fluidized gas supply device 6 is stopped, and the heat transfer medium heated by the solar superheater 10 is stopped. X is supplied as a fluidizing gas to the chamber 5a. Even when the inert gas is circulated, a certain amount leaks and needs to be replenished. Therefore, the supply of the inert gas is stopped and the superheated heat transfer medium X is supplied as a fluidized gas. The amount of active gas used can be reduced, and the operating cost is reduced.

  When the sunset time approaches and the energy of the superheat by the solar superheater 10 cannot be obtained, the supply of the heat transfer medium X from the fluidized steam supply unit 11 to the chamber 5a is stopped, and the fluidized gas supply device 6 supplies the chamber 5a. Restart the supply of inert gas. Further, when it approaches the sunset time, the cooling operation is switched to when the temperature of the heat transfer medium X falls below the saturation temperature, and then the operation is stopped.

  By operating the auxiliary boiler 4 before and after the sunrise time in this way, it is possible to advance the start timing of the dry operation possible period, and it is possible to dry the material to be dried Y in a longer period.

  As shown in FIG. 8, when the auxiliary boiler 4 is operated before and after the sunset time, the operation of the auxiliary boiler 4 is started before sunset. Accordingly, it is possible to suppress a decrease in the temperature of the heat transfer medium X before and after the sunset time. For this reason, the temperature of the heat transfer medium X can be maintained at the boiling point for a while even after the sunset time has passed, and the drying of the material to be dried Y can be continued. However, since the energy obtained from the sun is low while the auxiliary boiler 4 is operated, the heat transfer medium X cannot be overheated by the solar superheater 10. Accordingly, during this time, the supply of the heat transfer medium X from the fluidized steam supply unit 11 to the chamber 5a is stopped, and the fluidized gas Z made of an inert gas is supplied from the fluidized gas supply device 6 to the chamber 5a. In this way, by operating the auxiliary boiler 4 before and after the sunset time, it becomes possible to extend the drying operation possible period until after the sunset time as shown in FIG. Can be dried.

  Further, as shown in FIG. 9, when the auxiliary boiler 4 is operated before and after the sunrise time and before and after the sunset time, the start timing of the dry operation possible period is advanced, and further the dry operation available period is set to the sunset time. It becomes possible to extend until after the time.

  According to the drying system 1A of the present embodiment as described above, the solar superheater 10 that further raises the temperature of the heat transfer medium X heated by the solar collector 2 is provided. For this reason, the drying temperature in the drying furnace 5 can be further increased, and the material to be dried Y can be dried in a short time. Furthermore, according to the heat transfer medium X heated to the saturation temperature or higher, the temperature is sufficiently high, so that it does not aggregate even when it is in contact with the material to be dried Y being dried. For this reason, it becomes possible to use the heat transfer medium X as fluidized gas, and it becomes possible to reduce the usage-amount of an inert gas.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. In the description of the present embodiment, the description of the same parts as those of the first embodiment or the second embodiment is omitted or simplified.

  FIG. 10 is a flowchart showing a schematic configuration of the drying system 1B of the present embodiment. As shown in this figure, the drying system 1B of the present embodiment is provided side by side with a boiler power generation system 100 that uses the material to be dried Y (brown coal) dried by the drying system 1B of the present embodiment as a fuel. For the drying system 1A of the embodiment, a configuration including an intermediate pressure turbine bleed portion 12, a drying steam superheater 13 (superheater), and a low pressure turbine bleed portion 14 is adopted.

  The boiler power generation system 100 is not particularly limited in configuration, but a boiler 101 that generates steam by burning an object to be dried Y and a turbine 102 that generates rotational power using the steam obtained by the boiler 101. And. Although omitted in FIG. 10, the boiler power generation system 100 includes a generator that generates power using the rotational power generated by the turbine 102. In the present embodiment, the turbine 102 is a three-stage turbine including a high-pressure turbine 102a, an intermediate-pressure turbine 102b, and a low-pressure turbine 102c. The boiler 101 includes a reheater 101a that reheats the steam discharged from the high pressure turbine 102a and supplies the steam to the intermediate pressure turbine 102b.

  The intermediate pressure turbine bleed portion 12 includes a bleed pipe 12a and an open / close valve 12b. The extraction pipe 12a is a pipe that passes through the drying steam superheater 13 and connects the intermediate pressure turbine 102b and the low pressure turbine 102c. The opening / closing valve 12b is disposed in the middle of the extraction pipe 12a, and opens and closes the flow path formed by the extraction pipe 12a. The on-off valve 12b is controlled by the control device 8, for example. Such an intermediate-pressure turbine extraction unit 12 extracts steam from the intermediate-pressure turbine 102b, guides the extracted steam to pass through the drying steam superheater 13, and supplies the steam to the low-pressure turbine 102c.

  The drying steam superheater 13 is provided in parallel with the solar superheater 10 between the steam drum 3 and drying 5. The drying steam superheater 13 exchanges heat between the steam extracted from the intermediate pressure turbine 102 b by the intermediate pressure turbine extraction unit 12 and the heat transfer medium X arranged from the steam drum 3, so that the heat transfer medium X The temperature is further raised.

  The low-pressure turbine extraction unit 14 includes an extraction pipe 14a and an open / close valve 12b. The extraction pipe 12 a is connected to the low pressure turbine 102 c and guides the steam extracted from the low pressure turbine 102 c toward the heat transfer pipe 5 c of the drying furnace 5. The opening / closing valve 14b is disposed in the middle of the extraction pipe 14a, and opens and closes a flow path formed by the extraction pipe 14a. The on-off valve 14b is controlled by the control device 8, for example. Such a low-pressure turbine extraction unit 14 extracts steam from the low-pressure turbine 102 c and supplies it to the heat transfer tube 5 c of the drying furnace 5.

  According to the drying system 1B of the present embodiment as described above, the drying steam superheater 13 that further raises the temperature of the heat transfer medium X heated by the solar collector 2 is provided. For this reason, the drying temperature in the drying furnace 5 can be further increased, and the material to be dried Y can be dried in a short time. Furthermore, according to the heat transfer medium X heated to the saturation temperature or higher, the temperature is sufficiently high, so that it does not aggregate even when it is in contact with the material to be dried Y being dried. For this reason, it becomes possible to use the heat transfer medium X as fluidized gas, and it becomes possible to reduce the usage-amount of an inert gas.

  Further, in the drying system 1B of the present embodiment, a part of the steam extracted from the low pressure turbine 102c can be supplied to the heat transfer tube 5c of the drying furnace 5. Therefore, when the flow rate of the heat transfer medium X discharged from the steam drum 3 is small, it can be supplemented with steam from the low-pressure turbine 102c. For this reason, it is possible to extend the drying operation possible period, for example, it is possible to operate the drying system 1B for 24 hours.

  As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the configuration using a so-called fluidized bed type that performs drying while fluidizing the material to be dried Y has been described as the drying furnace 5. However, the present invention is not limited to this, and other drying furnaces can be used. For example, it is also possible to employ a configuration using a moving bed type drying furnace that supplies the material to be dried Y to an inclined surface and performs drying while moving the material to be dried Y by weight. However, the fluidized bed type drying furnace 5 described in the above embodiment can easily change the moving distance of the material to be dried Y by the arrangement interval of the dividing walls 5b, etc., and can arbitrarily set the drying time of the material to be dried Y. It is advantageous in that it can be adjusted.

  Moreover, in the said embodiment, the structure which drives the auxiliary boiler 4 in either or both of the sunrise time and the sunset time was demonstrated. However, the present invention is not limited to this, and the auxiliary boiler 4 may be operated when it is cloudy or rainy. In such a case, for example, the control device 8 determines whether or not to operate the auxiliary boiler 4 based on a sensor for detecting weather or weather information input from the outside.

  1 ... Drying system, 1A ... Drying system, 1B ... Drying system, 2 ... Solar collector, 2a ... First reflector, 2b ... Second reflector, 2c ... Heat transfer tube, 2d ... ... drive device, 2e ... support, 2f ... collecting pipe, 3 ... steam drum, 4 ... auxiliary boiler, 5 ... drying furnace, 5a ... chamber, 5b ... partition wall, 5b1 ... first Dividing wall, 5b2 ... second dividing wall, 5c ... heat transfer tube, 6 ... fluidized gas supply device (fluidized gas supply means, inert gas supply unit), 6a ... circulating piping, 6b ... inert Gas generator, 6c: Blower, 6d: Heat exchanger, 6e: Cooler, 7: Heat transfer medium circulating section, 7a: Return pipe, 7b: Condenser, 7c: Feed water pump 7d: Feed water preheater, 7e: Steam drum connection pipe, 8 ... Control device, 10 ... Solar superheater, 11 ... Flow Steam supply section (fluidized gas supply means, superheated steam supply section), 11a... Superheated steam supply pipe, 11b... Open / close valve, 12... Medium pressure turbine extraction section, 12a. , 13... Steam superheater (superheater) for drying, 14... Low pressure turbine bleed section, 14 a... Extraction piping, 14 b ...... Open / close valve, 100. Heater, 102 ... turbine, 102a ... high pressure turbine, 102b ... medium pressure turbine, 102c ... low pressure turbine, X ... heat transfer medium, Y ... to-be-dried, Z ... fluidized gas

Claims (8)

A solar collector that heats the heat transfer medium by solar heat and is provided in plurality;
A drying system comprising: a drying furnace that dries the object to be dried by exchanging heat between the heat transfer medium heated by the solar collector and the object to be dried.   A steam drum is provided between the solar collector and the drying furnace, and temporarily stores the heat transfer medium vaporized by being heated by the solar collector. The drying system according to claim 1.   The drying system according to claim 1, further comprising a superheater that further raises the temperature of the heat transfer medium heated by the solar heat collector.   The drying system according to any one of claims 1 to 3, further comprising fluidized gas supply means for fluidizing the material to be dried in the drying furnace by supplying fluidized gas to the drying furnace. .   The drying system according to claim 4, further comprising a superheated steam supply unit that supplies superheated steam as the fluidized gas to the drying furnace as the fluidized gas supply unit.   The drying system according to claim 4 or 5, further comprising an inert gas supply unit that supplies an inert gas as the fluidized gas to the drying furnace as the fluidized gas supply means.   The drying system according to claim 1, further comprising an auxiliary boiler that heats the heat transfer medium separately from the solar collector.   The drying system according to claim 7, further comprising a control device that operates the auxiliary boiler in accordance with at least one of a sunrise time and a sunset time.

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