JP6592953B2 - Heating unit and drying system - Google Patents

Description

  The present invention relates to a heating unit for heating an object to be heated such as hydrous coal, and a drying system for drying the object to be dried heated by the heating unit.

  Coal is a natural resource that can be stably supplied over a long period because it has a recoverable life of about 150 years, which is more than three times that of oil, and because the reserves are not unevenly distributed compared to oil. As expected. Coal is classified into peat, lignite, lignite, sub-bituminous coal, bituminous coal, semi-anthracite, and anthracite in order of increasing carbon content. Compared to anthracite and anthracite (hereinafter referred to as anthracite), the water content (water content) is high.

  Among hydrous coals, lignite is said to occupy half of the world's coal reserves, so effective utilization of lignite is being studied. However, as described above, hydrous coal such as lignite has a high moisture content compared to anthracite and the like, so the calorific value per unit weight is low, and the energy efficiency as fuel for transportation costs is low.

  Therefore, by supplying high-temperature steam from the bottom of the storage tank containing the hydrous coal, a fluidized bed of hydrous coal is formed in the storage tank, and the hydrous coal is dried by applying the heat of the steam to the hydrous coal. A furnace has been developed (for example, Patent Documents 1 and 2).

  However, when normal temperature hydrous coal is introduced into a drying furnace using water vapor, the water vapor is condensed by the hydrous coal at normal temperature, and the particles of the hydrous coal are agglomerated and the fluidity of the hydrous coal particles is impaired. May not be able to dry properly.

  Therefore, in Patent Document 1, a preheating container in which the hydrous coal circulates, a heat medium flow path that is disposed on the outer periphery of the preheating container and preheats the hydrous coal, a screw feeder that is disposed in the preheating container and feeds the hydrous coal to the drying furnace, The hydrous coal preheated by the preheater composed of is introduced into the drying furnace.

  In Patent Document 2, a fluidized bed of hydrous coal is formed using a non-condensable gas such as nitrogen or air as a fluidizing gas, and the hydrous coal is preheated by adding heat of the non-condensable gas to the hydrous coal. The water-containing coal is introduced into the drying furnace after preheating with a preheating device.

  Furthermore, as a technique for heating water-containing solid particles such as water-containing coal, by moving the water-containing solid particles from the top to the bottom, a moving layer of water-containing solid particles is formed, and hot air is circulated through the moving bed. Techniques for heating water-containing solid particles are disclosed (for example, Patent Documents 3 and 4).

JP 2013-178026 A JP 2013-178028 A Japanese Utility Model Publication No. 63-144599 Japanese Utility Model Publication No. 60-117470

  However, since the preheating device of Patent Document 1 is transferred only from the outer peripheral surface of the preheating container, the heat transfer area is small and the heating efficiency is low. Moreover, the energy required for the drive of the screw feeder which sends out hydrous coal will be applied. In the technique of Patent Document 2, energy for generating fluidized gas is required. In the techniques of Patent Documents 3 and 4, the heat of hot air is used to evaporate the water contained in the hydrous coal, and the coal itself cannot be efficiently heated.

  As described above, the conventional preheating apparatus has a problem that the object to be heated cannot be efficiently heated, and development of a technique that can efficiently heat the object to be heated is desired.

  Then, in view of such a subject, this invention aims at providing the heating unit which can heat a to-be-heated material efficiently, and a drying system.

In order to solve the above problems, a heating unit of the present invention includes a moving layer forming unit that forms a moving layer of an object to be heated, an upper heat transfer unit that is disposed in the moving layer forming unit and heats the object to be heated, A lower heat transfer section that is disposed below the upper heat transfer section in the moving layer forming section and heats the object to be heated.The upper heat transfer section and the lower heat transfer section have a flow path through which the heat medium flows. The heat medium flowing through the flow path of the upper heat transfer section is liquid, the heat medium flowing through the flow path of the lower heat transfer section is gas, and the heat medium flowing through the flow path of the lower heat transfer section is The heat energy is larger than that of the heat medium flowing through the flow path of the upper heat transfer section.

  Moreover, it is good also as providing the gas distribution means which distribute | circulates non-condensable gas toward the upper direction from the downward direction in a moving bed formation part.

  In order to solve the above problems, a drying system of the present invention includes a heating unit for heating an object to be dried, a drying furnace for drying the object to be dried heated by the heating unit, and a gas-liquid separation unit. The heating unit includes a moving layer forming unit that forms a moving layer of an object to be dried, an upper heat transfer unit that is disposed in the moving layer forming unit and heats the object to be dried, and a moving layer forming unit. A lower heat transfer section that is disposed below the upper heat transfer section and heats the object to be dried, and the drying furnace is disposed in the housing section that houses the object to be dried, And a drying furnace heat transfer section that heats the object to be dried, the gas-liquid separation unit gas-liquid separates the heat medium sent from the drying furnace heat transfer section, and heats the upper part The part and the lower heat transfer part have a flow path through which the heat medium flows, and the upper heat transfer part The heat medium flowing through the path is a liquid heat medium separated by the gas-liquid separation unit, and the heat medium flowing through the flow path of the lower heat transfer unit is the gas state heat separated by the gas-liquid separation unit. It is a medium.

  According to the present invention, an object to be heated can be efficiently heated.

It is a figure for demonstrating free water and combined water. It is a figure showing the schematic diagram of the drying system concerning a 1st embodiment. It is a figure which shows the schematic of the drying system concerning 2nd Embodiment. It is a figure for demonstrating the heating unit concerning the modification of 2nd Embodiment. It is a figure which shows the schematic of the drying system concerning 3rd Embodiment. It is a figure which shows the schematic of the drying system concerning 4th Embodiment. It is a figure which shows the schematic of the drying system concerning 5th Embodiment.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

(First embodiment: drying system 100)
FIG. 1 is a diagram for explaining free water and combined water. In addition, in FIG. 1, the ratio (water content of lignite) of the water contained in lignite is shown on a horizontal axis, and the temperature (degreeC) of the water vapor made to contact lignite is shown on a vertical axis. Water-containing coal such as lignite contains free water and combined water. Free water is water existing on the surface of hydrous coal and in macroscopic voids inside hydrous coal, and exhibits the same thermophysical properties as bulk water. The bound water is water condensed in the capillaries of hydrous coal, adsorbed water that is multilayered or single layered on the surface of hydrous coal, and bound water bound to hydrogen on the hydrous coal surface. Since the bound water is water that is harder to evaporate than the free water, in order to evaporate the bound water, larger heat energy is required than the free water. As shown in FIG. 1, when water vapor at 100 ° C. is brought into contact with lignite at normal pressure and heated, the moisture content of the lignite decreases to about 30%. Thus, the water which vaporizes at about 100 degreeC among the water contained in lignite is free water. On the other hand, when water vapor exceeding 100 ° C. and less than 200 ° C. is brought into contact with lignite and heated, the moisture content of lignite is reduced to about 3%. Thus, of the water contained in the lignite, the water that vaporizes above 100 ° C and below 200 ° C is the combined water. That is, free water requires less heat energy (vaporization heat, evaporation heat) required for vaporization than bound water. Therefore, in the present embodiment, first, free water is vaporized and removed from the object to be dried, and then the bound water is vaporized and removed from the object to be dried from which the free water has been removed. Here, the thermal energy is energy (kJ / mol) necessary for vaporizing water contained in the material to be dried.

  FIG. 2 is a diagram illustrating a schematic diagram of the drying system 100 according to the first embodiment. In FIG. 2, the flow of lignite is indicated by broken arrows, and the flow of gas such as water vapor and air is indicated by solid arrows. In this embodiment, a case where lignite is dried as an object to be dried will be described as an example.

  As shown in FIG. 2, the drying system 100 includes an object to be dried introduction unit 102, a first drying furnace 110, a second drying furnace 120, a cooling unit 130, and gas-liquid separation units 150 and 152. Composed.

  In the drying system 100 of the present embodiment, undried lignite is introduced into the first drying furnace 110 by the material to be dried introduction unit 102, and the first drying furnace 110 vaporizes and removes free water contained in the lignite, In the second drying furnace 120, the combined water contained in the lignite from which free water has been removed is vaporized and removed, and the lignite dried in the second drying furnace 120 is cooled by the cooling unit 130.

  Hereinafter, specific configurations of the first drying furnace 110, the second drying furnace 120, the cooling unit 130, and the gas-liquid separation units 150 and 152 will be described.

(First drying furnace 110)
The first drying furnace (drying furnace) 110 includes a first storage unit (storage unit) 112, a first fluidized gas supply unit 114, and a first heat transfer unit (drying furnace heat transfer unit) 116. Is done.

  The 1st accommodating part 112 accommodates the lignite introduced by the to-be-dried material introduction part 102. FIG. The first fluidizing gas supply unit 114 includes an air box 114a and blowers 114b and 114c for feeding the first fluidizing gas into the air box 114a. The wind box 114a is provided below the first housing part 112. When the drying system 100 is operated, the first fluidization is performed from the bottom surface of the first housing part 112 through the wind box 114a into the first housing part 112. Gas will be supplied.

  More specifically, the upper portion of the wind box 114a functions as a bottom surface of the first housing portion 112 and is formed of a dispersion plate 114d that can be ventilated. The dispersion plate 114d is configured by, for example, a plate provided with a plurality of openings having a diameter smaller than the particle size of lignite, or a plate provided with a nozzle provided with an opening having a diameter smaller than the particle size of lignite. .

  The blowers 114b and 114c send the first fluidizing gas into the wind box 114a. In this embodiment, the blower 114b collects water vapor (for example, 103 ° C., hereinafter referred to as “water vapor derived from free water”) generated by heating the lignite and vaporizing free water in the first housing portion 112. Is compressed (compressed) and fed into the wind box 114a as the first fluidizing gas. In addition, the blower 114c is a unit that collects water vapor (for example, 115 ° C., hereinafter referred to as “water vapor derived from combined water”) generated by heating the lignite in the second drying furnace 120 and vaporizing the combined water. Compressed (compressed) and sent to the wind box 114a as the first fluidized gas.

  Thus, the first fluidized gas supplied to the first accommodating part 112 by the first fluidizing gas supply part 114 causes the lignite to flow in the first accommodating part 112 to form a fluidized bed, and the first fluidized gas. A part of free water contained in the lignite is vaporized by bringing the gasified gas (water vapor at a high temperature (for example, about 30 kPaG, about 115 ° C.) into contact with the lignite.

  The first heat transfer unit 116 is constituted by, for example, a pipe through which a heat medium flows, and is arranged in the first housing unit 112. The first heat transfer unit 116 heats the lignite with the heat of the heat medium in the circulation process of the heat medium. In the present embodiment, the first heat transfer unit 116 is supplied with steam pressurized (compressed) by the blower 114e as a heat medium. The blower 114e pressurizes water vapor derived from free water and water vapor derived from combined water, that is, water vapor having a condensation temperature of about 100 ° C. to about 0.2 MPa. By doing so, the condensation temperature of the water vapor supplied to the first heat transfer section 116 can be raised to about 120 ° C.

  With the configuration including the first heat transfer unit 116, heat exchange is performed between the heat medium and the first fluidizing gas in the first housing unit 112, and the first fluidizing gas moving upward is further heated. can do. Therefore, drying of lignite (vaporization of free water) with the first fluidizing gas is further promoted.

  In addition, when heat exchange is performed between the heat medium and the first fluidizing gas in the first heat transfer unit 116 (the outer surface of the pipe constituting the first heat transfer unit 116), a part of the heat medium is transferred to the first heat transfer unit 116. It will condense in the hot part 116. Therefore, a gas-liquid separation unit 150 is provided, and the heat medium sent from the first heat transfer unit 116 is gas-liquid separated by the gas-liquid separation unit 150. In this way, the separated condensed heat medium (liquid water) is sent to the outside.

  As described above, in the first drying furnace 110, undried lignite is introduced into the first storage unit 112, and the lignite is heated by the first fluidizing gas supply unit 114 and the first heat transfer unit 116. Free water is vaporized and removed. On the other hand, the flow of lignite will be described. When undried lignite is introduced into the first housing portion 112, the volume of the introduced lignite and the volume of the fluidized bed increase. Then, the lignite (fluidized bed) from which the free water has been removed overflows from the outlet of the first housing part 112, and passes through the piping that connects the first housing part 112 and the second housing part 122 of the second drying furnace 120. 2 will be introduced into the accommodating portion 122. Further, free water (water vapor of about 103 ° C.) vaporized in the first drying furnace 110 is sent again to the wind box 114a by the blower 114b or supplied to the first heat transfer unit 116 by the blower 114e. It becomes.

(Second drying furnace 120)
The second drying furnace 120 includes a second storage unit 122, a second fluidized gas supply unit 124, and a second heat transfer unit 126.

  The second storage unit 122 stores lignite from which free water has been removed by the first drying furnace 110. Similarly to the first fluidizing gas supply unit 114 constituting the first drying furnace 110, the second fluidizing gas supply unit 124 includes an air box 124a and a blower 124b for feeding the second fluidizing gas into the air box 124a. Consists of including. The wind box 124a is provided below the second housing part 122. When the drying system 100 is operated, the second fluidization is performed from the bottom surface of the second housing part 122 through the wind box 124a into the second housing part 122. Gas will be supplied.

  More specifically, the upper portion of the wind box 124a functions as the bottom surface of the second housing portion 122 and is formed of a dispersion plate 124c that can be ventilated. The dispersion plate 124c is composed of, for example, a plate provided with a plurality of openings having a diameter smaller than the particle size of lignite, or a plate provided with a nozzle provided with an opening having a diameter smaller than the particle size of lignite. .

  The blower 124b sends the second fluidized gas into the wind box 124a. In the present embodiment, the blower 124b pressurizes (compresses) the recovered steam derived from the combined water and sends it to the wind box 124a as the second fluidized gas.

  Thus, the second fluidized gas supplied to the second accommodating part 122 by the second fluidized gas supply part 124 causes the lignite to flow in the second accommodating part 122 to form a fluidized bed and the second fluidized gas. A part of the bound water contained in the lignite is vaporized by bringing the gasified gas (water vapor at a high temperature (for example, about 0.3 kPaG, about 131 ° C.) into contact with the lignite.

  Similarly to the first heat transfer unit 116 that constitutes the first drying furnace 110, the second heat transfer unit 126 is configured by, for example, a pipe through which a heat medium flows, and is disposed in the second accommodating unit 122. The 2nd heat transfer part 126 heats lignite with the heat which a heat carrier has in the distribution process of a heat carrier. In the present embodiment, steam (for example, 200 ° C., 9 atm) generated in the steam turbine 140 is supplied to the second heat transfer unit 126 as a heat medium.

  With the configuration including the second heat transfer unit 126, heat exchange is performed between the heat medium and the second fluidizing gas in the second accommodating unit 122, and the second fluidizing gas moving upward is further heated. can do. Therefore, drying of lignite (vaporization of bound water) with the second fluidizing gas is further promoted.

  In addition, when heat exchange is performed between the heat medium and the second fluidized gas in the second heat transfer section 126 (the outer surface of the pipe constituting the second heat transfer section 126), part of the heat medium is transferred to the second heat transfer section. It will condense in the heat section 126. Therefore, a gas-liquid separation unit 152 is provided, and the heat medium sent from the second heat transfer unit 126 is gas-liquid separated by the gas-liquid separation unit 152. The separated and condensed heat medium (liquid water) is thus returned to the boiler constituting the steam turbine 140.

  As described above, in the second drying furnace 120, lignite from which free water has been removed is introduced into the second storage unit 122, and the lignite is heated by the second fluidized gas supply unit 124 and the second heat transfer unit 126. The bound water is vaporized and removed from the lignite. On the other hand, the flow of lignite will be described. When lignite from which free water has been removed is introduced from the first drying furnace 110 into the second storage unit 122, the volume of the introduced lignite and the volume of the fluidized bed increase. Then, the lignite (fluidized bed) from which the bound water has been removed overflows from the outlet of the second housing part 122, and the third housing is performed through a pipe that communicates the second housing part 122 and the third housing part 132 of the cooling unit 130. It will be introduced into the part 132. The combined water (water vapor of about 115 ° C.) vaporized in the second drying furnace 120 is sent again to the wind box 124a by the blower 124b or sent to the first drying furnace 110 by the blower 114c. It becomes.

(Cooling unit 130)
The cooling unit 130 includes a third storage unit 132 and a cooling gas supply unit 134. The 3rd accommodating part 132 accommodates the lignite from which combined water was removed by the 2nd drying furnace 120. FIG. As with the first fluidizing gas supply unit 114 and the second fluidizing gas supply unit 124, the cooling gas supply unit 134 includes a wind box 134a and a blower 134b that feeds a cooling gas (for example, air) into the wind box 134a. Consists of including. The air box 134a is provided below the third housing part 132. When the drying system 100 is operated, the cooling gas is supplied into the third housing part 132 from the bottom surface of the third housing part 132 through the air box 134a. Will be. By the structure provided with the cooling unit 130, the lignite from which free water and combined water have been removed can be cooled (for example, about 50 ° C.). The lignite that has been cooled in this way is sent to the lignite utilization facility at the subsequent stage.

  As described above, the drying system 100 according to the present embodiment removes free water in the first drying furnace 110 and removes combined water in the second drying furnace 120. That is, free water and combined water are removed stepwise in different drying furnaces.

  In the conventional configuration, since free water and combined water are vaporized at a time in one drying furnace, it is necessary to supply a heat medium having heat of vaporization (thermal energy) of the combined water to the heat transfer section. If it does so, it will vaporize with the heat medium (heat medium which has the heat of vaporization of combined water) also about free water whose vaporization heat is smaller than combined water, and the heat medium which has the heat energy of overspec Was supposed to be generated.

  However, in the drying system 100 according to the present embodiment, it is only necessary to supply the first heat transfer unit 116 with a heat medium (water vapor) having vaporization heat that can vaporize at least free water. Therefore, it is possible to reduce the cost of the apparatus itself and the running cost for generating the heat medium to be circulated through the first heat transfer unit 116 as compared with the conventional case.

  Further, steam generated in the steam turbine 140 is circulated as a heat medium in the second heat transfer section 126 of the second drying furnace 120. In recent years, means for utilizing thermal energy of steam generated in the steam turbine 140 has been developed, but efficient utilization means have not been developed yet. Therefore, in order to vaporize the bound water of the lignite, it is possible to dry the lignite (evaporate the bound water of the lignite) while efficiently using the thermal energy of the steam by using the thermal energy of the steam. It becomes possible. Therefore, it is possible to reduce the cost of the device itself for generating a high-temperature and high-pressure heat medium and the energy consumption of this device, as compared with the conventional case.

  Furthermore, since the steam used as the heat medium in the second heat transfer section 126 can be returned to the steam turbine 140 by the configuration including the gas-liquid separation unit 152, the steam can be effectively used.

  Moreover, the 1st fluidization gas supply part 114 of this embodiment is supplying the water vapor | steam derived from free water and the water vapor | steam derived from combined water to the 1st accommodating part 112, and the 1st heat-transfer part 116 is used as a heat medium. Since water vapor derived from free water and water vapor derived from combined water are circulated, the latent heat of water vapor derived from free water and water vapor derived from combined water can be effectively utilized (recovered), and energy efficiency can be improved. It becomes possible. Similarly, since the second fluidized gas supply unit 124 supplies the water vapor derived from the combined water to the second storage unit 122, the sensible heat of the water vapor derived from the combined water can be effectively used (recovered). .

(Second Embodiment: Drying System 200)
As described above, water vapor is introduced as the first fluidizing gas into the first storage unit 112 of the first drying furnace 110, but when normal temperature lignite is introduced into the first storage unit 112, When the brown coal at normal temperature and water vapor come into contact with each other, the water vapor may condense and become water. Brown coal may be agglomerated by such water (liquid), and when agglomerated, agglomerated aggregates (so-called agglomerates) are formed. Since the agglomerate has extremely low fluidity, if an agglomerate is generated in the first accommodating portion 112, formation of a fluidized bed becomes difficult, and there is a possibility that the lignite cannot be dried normally. Therefore, in this embodiment, the lignite before being introduced into the first drying furnace 110 is preheated.

  FIG. 3 is a diagram illustrating a schematic diagram of a drying system 200 according to the second embodiment. In FIG. 3, the flow of lignite is indicated by broken arrows, and the flow of water vapor and water is indicated by solid arrows. As shown in FIG. 3, the drying system 200 includes an object introduction unit 202, a heating unit 210, a first drying furnace 110, a second drying furnace 120, a cooling unit 130, a gas-liquid separation unit 150, 152. In addition, about the structure substantially equal to the structure of the said drying system 100, the same code | symbol is attached | subjected and description is abbreviate | omitted, and here the to-be-dried material introduction part 202 and the heating unit 210 are explained in full detail.

  The to-be-dried material introducing unit 202 introduces undried lignite into the heating unit 210. The heating unit 210 includes a moving layer forming unit 212, an upper heat transfer unit 214, and a lower heat transfer unit 216.

  The moving layer forming unit 212 accommodates the undried lignite (substance to be heated) introduced by the to-be-dried material introducing unit 202 and moves the lignite from the upper part to the lower part by the own weight of the lignite, A moving layer is formed.

  The upper heat transfer section 214 is disposed in the moving bed forming section 212, has a flow path through which the heat medium flows, and heats the lignite. In the present embodiment, the upper heat transfer section 214 includes a pipe through which a heat medium flows. The upper heat transfer unit 214 heats the lignite by exchanging heat between the heat medium and the lignite through the partition walls constituting the piping in the course of the circulation of the heat medium, as the heat medium circulates in the pipe. In the present embodiment, the liquid (120 ° C. water) that has been gas-liquid separated by the gas-liquid separation unit 150 as a heat medium is supplied to the upper heat transfer section 214 by the pump 214a. That is, the condensed heat medium is supplied among the used heat medium that has circulated through the first heat transfer unit 116 of the first drying furnace 110.

  The lower heat transfer unit 216 is disposed below the upper heat transfer unit 214 in the moving bed forming unit 212, has a flow path through which the heat medium flows, and heats the lignite. In the present embodiment, the lower heat transfer unit 216 includes a pipe through which a heat medium flows, similarly to the upper heat transfer unit 214. The lower heat transfer unit 216 heats the lignite by exchanging heat between the heat medium and the lignite through the partition walls constituting the piping in the circulation process of the heat medium, as the heat medium circulates in the pipe. In the present embodiment, the lower heat transfer section 216 has a gas (120 ° C. water vapor) separated by the gas-liquid separation unit 150 as a heat medium, that is, the first heat transfer section 116 of the first drying furnace 110. Of the used heat medium that has circulated, a heat medium maintained in a gaseous state is supplied. Even if the gas (gas state heat medium) separated by the gas-liquid separation unit 150 has the same temperature, the heat energy that can be imparted to the lignite is greater than the liquid (condensed heat medium) by the amount of latent heat. large. Therefore, it can be said that the heat medium flowing through the flow path of the lower heat transfer unit 216 has larger heat energy than the heat medium flowing through the upper heat transfer unit 214.

  That is, in the moving bed forming unit 212, the lignite is first heated by the upper heat transfer unit 214 and then heated by the lower heat transfer unit 216. Here, when the heat medium of the upper heat transfer section 214 has larger (higher) heat energy than the lower heat transfer section 216, sufficient heat transfer is not performed depending on the movement speed of the lignite, and a moving bed is formed. There is a possibility that the lignite is not preheated at the lower part of the portion 212. In the heating unit 210 of the present embodiment, the heat medium flowing through the lower heat transfer section 216 has a larger heat energy than the heat medium flowing through the upper heat transfer section 214, so that the lignite at room temperature is gradually (gradually) In addition, the lignite can be efficiently preheated (heated) in the moving bed forming section 212.

  In addition, since the upper heat transfer section 214 and the lower heat transfer section 216 are arranged in the moving bed forming section 212, a larger heat transfer area can be taken compared to a preheating device equipped with a conventional screw feeder. It becomes possible to improve the heating efficiency of lignite.

  Furthermore, as the heating unit 210 is provided with a moving bed forming unit 212 that forms a moving bed, the lignite moves by its own weight, so that the power for moving the lignite can be reduced.

  Thus, when heat exchange is performed between the heat medium and the lignite in the lower heat transfer section 216, a part of the heat medium is condensed. Therefore, the gas-liquid separation unit 220 is provided, and the condensed heat medium sent from the upper heat transfer unit 214 and the heat medium sent from the lower heat transfer unit 216 are combined by the gas-liquid separation unit 220. Gas-liquid separation. Then, the condensed heat medium (liquid water) separated by the gas-liquid separation unit 220 is sent to the outside.

  As described above, according to the drying system 200 according to the present embodiment, the configuration including the heating unit 210 can preheat lignite at normal temperature and introduce it into the first drying furnace 110. Therefore, even if the lignite and the first fluidized gas (steam) come into contact with each other in the first drying furnace 110, the condensation of the steam can be reduced, and the aggregation of the lignite can be suppressed. Moreover, since the heating unit 210 preheats lignite with the heat medium used in the first drying furnace 110, it is possible to reduce energy required for preheating the lignite.

(Modification of the second embodiment)
FIG. 4 is a diagram for explaining a heating unit 250 according to a modification of the second embodiment. As shown in FIG. 4, the heating unit 250 includes a moving bed forming part 212, an upper heat transfer part 214, a lower heat transfer part 216, and a gas flow means 260. In addition, about the structure substantially equal to the structure of the said heating unit 210, the same code | symbol is attached | subjected and description is abbreviate | omitted and the gas distribution means 260 is explained in full detail here.

  The gas distribution means 260 is configured to include, for example, a blower, piping, and the like, and distributes non-condensable gas from the lower side to the upper side in the moving bed forming unit 212. In the present embodiment, the gas flow means 260 introduces non-condensable gas from the lower part of the moving bed forming unit 212 and discharges it from the upper part of the moving bed forming unit 212. Here, the non-condensable gas is a gas that does not condense even when it contacts lignite in the moving bed forming unit 212, and is, for example, air or nitrogen.

  Due to the configuration including the gas flow means 260, the residence time of the lignite in the moving bed forming part 212 can be extended, and the heating efficiency (heat transfer efficiency) of the lignite by the upper heat transfer part 214 and the lower heat transfer part 216 is improved. Is possible.

(Third embodiment: Drying system 300)
In 1st Embodiment mentioned above, the 2nd fluidization gas supply part 124 of the 2nd drying furnace 120 supplies the water vapor | steam derived from combined water directly as a 2nd fluidization gas, and forms the fluidized bed of lignite. Explained with an example. However, the second fluidizing gas supply unit may supply the second storage unit 122 with heated water vapor derived from the combined water as the second fluidizing gas.

  FIG. 5 is a diagram illustrating a schematic diagram of a drying system 300 according to the third embodiment. In FIG. 5, the flow of lignite is indicated by broken arrows, and the flow of water vapor is indicated by solid arrows. As shown in FIG. 5, the drying system 300 includes an object introduction unit 102, a first drying furnace 110, a second drying furnace 320, a cooling unit 130, and gas-liquid separation units 150 and 152. Composed. In addition, about the structure substantially equal to the structure of the said drying system 100, the same code | symbol is attached | subjected and description is abbreviate | omitted and the 2nd drying furnace 320 is explained in full detail here.

  The second drying furnace 320 includes a second storage unit 122 and a second fluidized gas supply unit 324. The 2nd fluidization gas supply part 324 of this embodiment heats the water vapor | steam derived from combined water as 2nd fluidization gas, and supplies it to the 2nd accommodating part 122. FIG.

  More specifically, the second fluidizing gas supply unit 324 includes an air box 124a, a blower 324b for feeding the fluidizing gas to the air box 124a, and a heating unit 324c, like the second fluidizing gas supply unit 124. It is comprised including. The heating unit 324c is constituted by, for example, a heat exchanger, and heats the water vapor derived from the combined water by exchanging heat between the water vapor derived from the combined water and the steam generated in the steam turbine 140.

  And the blower 324b sends what was further heated (for example, 250 degreeC) by compressing the heated water vapor | steam to the wind box 124a as 2nd fluidization gas.

  As described above, according to the drying system 300 according to the present embodiment, the second fluidizing gas supply unit 324 supplies the water vapor derived from the combined water heated by the heating unit 324c to the second storage unit 122. Compared with the case where water vapor derived from combined water is used as the second fluidizing gas, the combined water can be vaporized using only the second fluidizing gas. Therefore, the second heat transfer unit 126 can be omitted, and the cost required for the second heat transfer unit 126 can be reduced.

  In addition, the heating unit 324c efficiently uses the heat energy of steam that has not been developed as an effective utilization means by using steam generated in the steam turbine 140 as a heating source of water vapor derived from combined water. It becomes possible to do.

(Fourth embodiment: drying system 400)
In the first embodiment described above, a configuration in which the second fluidizing gas supply unit 124 of the second drying furnace 120 supplies steam as the second fluidizing gas to form a fluidized bed of brown coal will be described as an example. did. However, the second fluidizing gas supply unit may supply a gas other than water vapor to the second accommodating unit 122 as the second fluidizing gas.

  FIG. 6 is a schematic diagram of a drying system 400 according to the fourth embodiment. In FIG. 6, the flow of lignite is indicated by broken arrows, and the flow of water vapor and combustion exhaust gas is indicated by solid arrows. As illustrated in FIG. 6, the drying system 400 includes an object to be dried introduction unit 102, a first drying furnace 110, a second drying furnace 420, a cooling unit 130, and gas-liquid separation units 150 and 152. Composed. In addition, about the structure substantially equal to the structure of the said drying system 100, the same code | symbol is attached | subjected and description is abbreviate | omitted, and here the 2nd drying furnace 420 is explained in full detail.

  The second drying furnace 420 includes a second storage unit 122 and a second fluidized gas supply unit 424. The 2nd fluidization gas supply part 424 of this embodiment supplies combustion exhaust gas to the 2nd storage part 122 as the 2nd fluidization gas. Here, the combustion exhaust gas is a high-temperature gas generated by burning fuel such as oil or coal.

  More specifically, the second fluidizing gas supply unit 424 includes an air box 124a and a blower 424b for feeding the second fluidizing gas into the air box 124a, like the second fluidizing gas supply unit 124. Composed. The blower 424b sends the combustion exhaust gas (for example, 80 ° C.), which has been further heated (for example, 95 ° C.) to the wind box 124a as the second fluidizing gas.

  The combustion exhaust gas is a non-condensable gas and contains almost no water vapor. Therefore, when supplied as the second fluidizing gas into the second accommodating portion 122, the combustion exhaust gas is compared with the case where water vapor is supplied as the second fluidizing gas. Thus, the concentration of water vapor (water vapor pressure) in the second housing part 122 can be reduced. Thereby, when combustion exhaust gas is supplied as 2nd fluidization gas, it becomes possible to vaporize combined water in the 2nd accommodating part 122 at low temperature rather than water vapor | steam.

  Therefore, the second fluidizing gas supply unit 424 supplies combustion exhaust gas as the second fluidizing gas, so that the energy required for cooling in the cooling unit 130 can be reduced. Further, since the combustion exhaust gas contains almost no oxygen, it is possible to avoid a situation where lignite is burned by oxygen.

  In the drying system 400 of the present embodiment, the gas delivered from the second storage unit 122 includes combustion exhaust gas in addition to the steam derived from the combined water. Therefore, in the first drying furnace 110, the second storage unit The first fluidizing gas supply unit 114 supplies the water vapor derived from free water to the first storage unit 112 without using the gas sent from 122, and the first heat transfer unit 116 supplies the water vapor derived from free water. It will be distributed.

(Fifth embodiment: drying system 500)
In the first embodiment described above, the configuration in which the second heat transfer unit 126 of the second drying furnace 120 directly distributes the steam generated in the steam turbine 140 as a heat medium has been described as an example. However, the heat medium that circulates through the second heat transfer section is not limited to steam.

  FIG. 7 is a schematic diagram of a drying system 500 according to the fifth embodiment. In FIG. 7, the flow of lignite is indicated by broken arrows, and the flow of water vapor is indicated by solid arrows. As shown in FIG. 7, the drying system 500 includes an object to be dried introduction unit 102, a first drying furnace 110, a second drying furnace 520, a cooling unit 130, and gas-liquid separation units 150 and 152. Composed. In addition, about the structure substantially equal to the structure of the said drying system 100, the same code | symbol is attached | subjected and description is abbreviate | omitted and the 2nd drying furnace 520 is explained in full detail here.

  The second drying furnace 520 includes a second storage unit 122, a second fluidized gas supply unit 124, a second heat transfer unit 526, and a mixer (injector) 528. The second heat transfer unit 526 causes the mixed medium generated by the mixer 528 to flow as a heat medium.

  The mixer 528 mixes steam (for example, 200 ° C., 9 atm) generated in the steam turbine 140 with steam (for example, 115 ° C., 1 atm) derived from combined water sent from the second storage unit 122, and steam is mixed. A cooler mixed medium (eg, 145 ° C., 4 atm) is produced.

  The temperature and pressure of the steam generated by the steam turbine 140 are determined in advance, but this steam may be over-spec in order to vaporize the bound water. That is, even if steam is mixed with low-temperature and low-pressure steam to reduce the heat energy of the heat medium, the bound water can be vaporized.

  Accordingly, as in the drying system 500 according to the present embodiment, the lignite is provided with a mixer 528 that mixes steam and steam derived from the combined water to generate a mixed medium, thereby reducing the amount of steam used. It becomes possible to vaporize the bound water contained in the water.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Is done.

  For example, in the above-described embodiment, lignite has been described as an example of the material to be dried. However, if it comprises free water and combined water, it can be dried as an object to be dried.

  Moreover, in the said 1st Embodiment, the 1st fluidization gas supply part 114 mentioned and demonstrated as an example the structure which utilizes the water vapor derived from free water and the water vapor derived from combined water as 1st fluidization gas. However, the first fluidizing gas supply unit may use either water vapor derived from free water or water vapor derived from combined water as the first fluidizing gas, or use other water vapor from different supply sources. May be. In addition, another gas not containing oxygen can be used as the first fluidizing gas.

  Moreover, in the said 1st Embodiment, the 1st heat-transfer part 116 mentioned and demonstrated as an example the structure which distribute | circulates the water vapor derived from free water and the water vapor derived from combined water as a heat medium. However, the first heat transfer section may use either water vapor derived from free water or water vapor derived from bound water as a heat medium, or use other water vapor or fluid other than water vapor with different supply sources. May be.

  Moreover, in the said 1st Embodiment, the 2nd fluidization gas supply part 124 mentioned and demonstrated as an example the structure which utilizes the water vapor | steam derived from combined water as a 2nd fluidization gas. However, the second fluidizing gas supply unit may use other water vapor having a different supply source as the second fluidizing gas.

  In the third embodiment, the configuration in which the heating unit 324c uses steam generated in the steam turbine 140 as a heating source has been described as an example. However, the heating source of the heating unit 324c is not limited to steam, and may be, for example, an electric heater.

  In the fourth embodiment, the configuration in which the second fluidizing gas supply unit 424 uses combustion exhaust gas as the second fluidizing gas has been described as an example. However, the second fluidizing gas supply unit may use other non-condensable gas containing almost no oxygen and water vapor as the second fluidizing gas.

  Moreover, in the said 1st Embodiment, the 2nd heat-transfer part 126 mentioned as an example the structure which distribute | circulates the water vapor | steam (steam) generated with the steam turbine 140 as a heat medium. However, the second heat transfer section replaces the steam generated in the steam turbine 140 or, in addition to the steam generated in the steam turbine 140, other steam (for example, low-pressure steam supplied from the outside) with a different supply source, A fluid other than water vapor may be used.

  In the second embodiment, of the heat medium sent from the first heat transfer unit 116, the condensed heat medium is transferred to the upper heat transfer unit 214, and the gaseous heat medium is transferred to the lower heat transfer unit 216. The supplied configuration has been described as an example. However, a heat medium having a larger heat energy than the heat medium that flows through the upper heat transfer section may flow through the lower heat transfer section.

  The drying systems 300, 400, and 500 may include the heating unit 210 or the heating unit 250.

  Moreover, the 1st drying furnace 110, the 2nd drying furnace 120, 320, 420, 520, and the cooling unit 130 may be comprised by one accommodating part, and may be comprised including the some accommodating part. Similarly, the heating units 210 and 250 may be configured by one moving layer forming unit 212 or may include a plurality of moving layer forming units.

  Moreover, in the said 1st Embodiment, the 1st drying furnace 110 mentioned and demonstrated the structure which forms the fluidized bed of lignite. However, the 1st drying furnace 110 should just be able to dry lignite, and does not necessarily need to form the fluidized bed of lignite. For example, the first drying furnace may form a moving bed of lignite. In this case, the first fluidizing gas supply unit 114 can be omitted.

  INDUSTRIAL APPLICABILITY The present invention can be used in a heating unit that heats an object to be heated such as hydrous coal, and a drying system that dries the object to be dried heated by the heating unit.

100 Drying system 110 First drying furnace (drying furnace)
112 1st accommodating part (accommodating part)
116 1st heat transfer section (drying furnace heat transfer section)
150 Gas-liquid separation unit 200 Drying system 210 Heating unit 212 Moving layer forming unit 214 Upper heat transfer unit 216 Lower heat transfer unit 250 Heating unit 260 Gas distribution means 300 Drying system 400 Drying system 500 Drying system

Claims (3)

A moving layer forming part for forming a moving layer of an object to be heated;
An upper heat transfer section arranged in the moving layer forming section and heating the object to be heated;
A lower heat transfer section that is disposed below the upper heat transfer section in the moving layer forming section and heats the object to be heated;
With
The upper heat transfer section and the lower heat transfer section have a flow path through which a heat medium flows,
The heat medium flowing through the flow path of the upper heat transfer section is liquid, and the heat medium flowing through the flow path of the lower heat transfer section is gas,
The heating unit, wherein the heat medium flowing through the flow path of the lower heat transfer unit has larger thermal energy than the heat medium flowing through the flow path of the upper heat transfer unit.   2. The heating unit according to claim 1, further comprising a gas distribution unit configured to distribute a non-condensable gas from below to above in the moving bed forming unit. A drying system including a heating unit for heating an object to be dried, a drying furnace for drying the object to be dried heated by the heating unit, and a gas-liquid separation unit,
The heating unit is
A moving layer forming part for forming a moving layer of the material to be dried;
An upper heat transfer section that is arranged in the moving layer forming section and heats the material to be dried;
A lower heat transfer section that is disposed below the upper heat transfer section in the moving layer forming section and heats the material to be dried;
With
The drying furnace
An accommodating portion for accommodating the object to be dried;
A drying furnace heat transfer section that is disposed in the housing section and has a flow path through which a heat medium flows, and heats the object to be dried;
With
The gas-liquid separation unit gas-liquid separates the heat medium sent from the drying furnace heat transfer section,
The upper heat transfer section and the lower heat transfer section have a flow path through which a heat medium flows,
The heat medium flowing through the flow path of the upper heat transfer section is a liquid heat medium separated by the gas-liquid separation unit,
The drying system, wherein the heat medium flowing through the flow path of the lower heat transfer section is a gas state heat medium separated by the gas-liquid separation unit.

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