JP5009833B2 - Heat storage device - Google Patents

Description

  The present invention relates to a heat storage device that stores waste heat generated in a heat source facility such as a power plant or a waste incineration plant.

  Waste heat generated in heat source facilities (for example, power plants, waste incinerators, steelworks, chemical plants) is effectively discarded in heat utilization facilities (for example, office buildings, hospitals, hotels, and Kurhaus). There is known a heat storage device that stores heat in a heat storage tank, transports the heat storage tank to a heat utilization facility, and performs hot water supply, heating, or the like using the heat storage tank as a heat source (Patent Document 1).

  The heat storage device includes a heat storage tank that stores the latent heat storage material and the heat transfer oil in a state separated into upper and lower layers, a supply pipe that supplies the heat transfer oil into the latent heat storage material layer in the heat storage tank, and A recovery pipe for recovering the heat transfer oil from the heat transfer oil layer in the heat storage tank, and circulating the heat transfer oil between the heat source facility (or heat utilization facility) and the heat storage tank through the supply pipe and the recovery pipe use. At this time, the heat transfer oil supplied from the supply pipe into the latent heat storage material layer is heated in direct contact with the latent heat storage material while rising in the latent heat storage material layer due to the specific gravity difference between the heat transfer oil and the latent heat storage material. Exchange.

  Here, the latent heat storage material is a heat storage material that stores and releases heat using heat (latent heat) that is absorbed and exhausted when a substance undergoes a phase change between a solid phase and a liquid phase. When the phase changes, the heat is absorbed from the surroundings, and when the phase changes from the liquid phase to the solid phase, the heat is dissipated. Moreover, since the temperature of the latent heat storage material does not change when the phase changes between the solid phase and the liquid phase, it is possible to radiate heat at a constant temperature. As such a latent heat storage material, for example, sodium acetate trihydrate, magnesium chloride hexahydrate, erythritol, and mannitol are used.

Examples of the shape of the heat storage tank include a cylindrical shape whose central axis is substantially horizontal and whose cross section perpendicular to the central axis is circular, elliptical, or polygonal whose bottom is narrowed.
JP 2007-13269 A

  By the way, when storing heat in said heat storage apparatus, as shown in FIG. 5, in the latent heat storage material layer 32 in the heat storage tank 31, the area | region 34 where the heat transfer oil supplied from the supply pipe | tube 33 passes, and the area | region which does not pass 35, and the solid phase latent heat storage material 36 in the region 34 through which the heat transfer oil passes is in direct contact with the heat transfer oil and receives heat, so it melts in a short time, but the region through which the heat transfer oil does not pass Since the solid phase latent heat storage material 37 in 35 receives heat via the liquid phase latent heat storage material 38 in the region 34 through which the heat transfer oil passes, it hardly melts. Therefore, it takes a long time until all the latent heat storage material 37 is melted, and it is difficult to use the latent heat storage material in the region 35 through which the heat transfer oil does not pass without waste.

  The problem to be solved by the present invention is to provide a heat storage device capable of storing heat in a short time without waste.

  In order to solve the above problems, the shape of the heat storage tank is such that the solid phase latent heat storage material in the region where the heat transfer oil in the latent heat storage material layer does not pass slides down to the region through which the heat transfer oil passes. A configuration having an inclined inner surface and a friction reducing means for reducing friction with a solid phase latent heat storage material is provided in the inclined inner surface of the heat storage device.

  In this heat storage device, when heat medium oil with waste heat is supplied from the supply pipe into the latent heat storage material layer from a state where the latent heat storage material layer is almost in a solid phase, the heat medium oil in the latent heat storage material layer is In the passing region, the latent heat storage material melts in a short time into a liquid phase, but in the region where the heat transfer oil does not pass, the latent heat storage material remains in a solid phase and rides on the inclined inner surface of the heat storage tank. Here, since the frictional force of the inclined inner surface is kept low by the friction reducing means, the solid phase latent heat storage material in the area where the heat transfer oil does not pass slides down to the area where the heat transfer oil passes by its own weight. It melts in a short time in direct contact with the heat transfer oil.

  Examples of the friction reducing means include a low friction film formed on the inclined inner surface, a polished surface formed on the inclined inner surface, a heating mechanism for heating the inclined inner surface, and the like. Examples of the heating mechanism include a heat source fluid flow path provided along the outer surface of the heat storage tank.

  Further, when extracting heat from the heat storage device, if the solid phase latent heat storage material in the region through which the heat transfer oil does not pass slides down to the region through which the heat transfer oil passes, the latent heat storage material grows, There is a possibility that the supply of the heat transfer oil from the supply pipe may be hindered. Therefore, it is preferable that heating by the heating mechanism can be released. In this way, when the heat is taken out from the heat storage device, the frictional force between the inclined inner surface and the solid phase latent heat storage material can be secured by releasing the heating by the heating mechanism. It becomes possible to prevent the heat storage material from slipping down.

  In addition, examples of the shape of the heat storage tank include a cylindrical shape whose central axis is substantially horizontal and whose cross section perpendicular to the central axis is circular, elliptical, or polygonal whose bottom is narrowed. . Here, “substantially horizontal” does not need to be horizontal in a strict sense, but is horizontal in a sense that allows inclination for discharging the liquid in the heat storage tank.

  In the heat storage device of the present invention, the solid phase latent heat storage material in the region where the heat transfer oil in the latent heat storage material layer does not pass easily slides down to the region through which the heat transfer oil passes, Melts in a short time by direct contact with heat transfer oil. Therefore, this heat storage device can store heat in the latent heat storage material in the heat storage tank in a short time without waste.

  In FIG. 1, waste heat generated in a heat source facility 1 (for example, a power plant, a waste incineration plant, a steel mill, a chemical plant) is converted into a heat utilization facility 2 (for example, an office building, a hospital, a hotel, This shows a heat transfer system that can be used in Kurhaus.

  In this heat transfer system, a heat source pipe 3, a heat medium pipe 4, and a heat exchanger 5 that performs heat exchange between the heat source pipe 3 and the heat medium pipe 4 are provided on the heat source facility 1 side. The heat source pipe 3 is connected to the heat source facility 1, and a heat source fluid (for example, hot water or steam) having waste heat circulates between the heat source facility 1 and the heat exchanger 5. The heat medium pipe 4 is detachably connected to the heat storage device 6 according to the embodiment of the present invention. When the circulation pump 7 provided in the middle of the heat medium pipe 4 is operated, the heat exchanger 5 and the heat storage device 6 are connected. Heat medium oil circulates between them, heat is transmitted from the heat source pipe 3 to the heat storage device 6 through the heat medium oil, and heat is stored.

  Moreover, this heat transfer system is provided with a heat utilization pipe 8, a heat medium pipe 9, and a heat exchanger 10 that performs heat exchange between the heat utilization pipe 8 and the heat medium pipe 9 on the heat utilization facility 2 side. It has been. The heat utilization pipe 8 is connected to the heat utilization facility 2, and a heat utilization medium (for example, hot water supply water or heating water) is circulated between the heat utilization facility 2 and the heat exchanger 10. The heat medium pipe 9 is detachably connected to the heat storage device 6. When the circulation pump 11 provided in the middle of the heat medium pipe 9 is operated, the heat medium oil is exchanged between the heat storage device 6 and the heat exchanger 10. It circulates and heat is transmitted from the heat storage device 6 to the heat utilization pipe 8 via the heat transfer oil, and hot water supply or heating in the heat utilization facility 2 becomes possible using the heat.

  In this heat transfer system, the waste heat of the heat source facility 1 can be used as the heat energy of the heat utilization facility 2 by moving the heat storage device 6 between the heat source facility 1 and the heat utilization facility 2 described above.

  As shown in FIGS. 2 and 3, the heat storage device 6 includes a heat storage tank 12 having a substantially horizontal cylindrical central axis and a circular cross section perpendicular to the central axis. In the heat storage tank 12, the latent heat storage material 13 and the heat transfer oil 14 are accommodated in a state of being separated into upper and lower layers. The latent heat storage material 13 absorbs heat from the surroundings when the phase changes from the solid phase to the liquid phase, and dissipates heat when the phase changes from the liquid phase to the solid phase. As such latent heat storage material 13, for example, erythritol, mannitol, sodium acetate trihydrate, magnesium chloride hexahydrate, or the like can be used.

  The heat medium oil 14 has a specific gravity smaller than that of the latent heat storage material 13 and floats on the surface of the latent heat storage material 13 due to a difference in specific gravity with the latent heat storage material 13. Further, an air layer 15 is provided in the heat storage tank 12, and the air layer 15 absorbs volume changes of the latent heat storage material layer 16 and the heat transfer oil layer 17.

  Further, the heat storage tank 12 is provided with a supply pipe 18 for supplying the heat medium oil 14 into the latent heat storage material layer 16 and a recovery pipe 19 for recovering the heat medium oil 14 from the heat medium oil layer 17. The supply pipe 18 is disposed substantially parallel to the central axis of the heat storage tank 12, and a number of downward discharge ports 20 for discharging the heat transfer oil 14 into the latent heat storage material layer 16 are formed at intervals in the longitudinal direction. Yes.

  As shown in FIG. 3, the latent heat storage material layer 16 in the heat storage tank 12 includes a region 21 through which the heat transfer oil 14 supplied from the supply pipe 18 passes and a region 22 through which the heat transfer oil 14 does not pass. is there. The heat storage tank 12 is inclined so that the solid phase latent heat storage material 13 in the region 22 through which the heat transfer oil 14 does not pass slides down to the region 21 through which the heat transfer oil 14 passes in the latent heat storage material layer 16. A low-friction film (for example, a hydrophobic film such as a fluororesin coating or a silicon resin coating) that reduces friction with the solid-phase latent heat storage material 13 on the entire inner surface of the heat storage tank 12 including the inclined inner surface 23. ) 24 is given.

  When heat is stored in the heat storage device 6, the supply pipe 18 and the recovery pipe 19 of the heat storage device 6 are connected to the heat medium pipe 4 of the heat source facility 1, and the circulation pump 7 is operated in that state. The heat transfer oil 14 is circulated between the heat exchangers 5. At this time, the heat transfer oil 14 is discharged from the supply pipe 18 into the latent heat storage material layer 16, and the heat transfer oil 14 rises in the latent heat storage material layer 16 due to the specific gravity difference with the latent heat storage material 13. In the rising process, the latent heat storage material 13 in the region 21 through which the heat transfer oil 14 passes directly contacts the heat transfer oil 14 to receive heat, and changes from the solid phase to the liquid phase. Further, the solid phase latent heat storage material 13 in the region 22 through which the heat transfer oil 14 does not pass slides down to the region 21 through which the heat transfer oil 14 passes along the inclined inner surface 23 of the heat storage tank 12, and the latent heat that has slipped down. The heat storage material 13 directly contacts the heat transfer oil 14 discharged from the supply pipe 18 and melts in a short time. Moreover, the contact between the latent heat storage material 13 and the heat transfer oil 14 is promoted by the flow in the heat storage tank 12 generated when the solid phase latent heat storage material 13 slides down.

  On the other hand, when extracting heat from the heat storage device 6, the supply pipe 18 and the recovery pipe 19 of the heat storage device 6 are connected to the heat medium pipe 9 of the heat utilization facility 2, and the circulation pump 11 is operated in this state to store the heat. The heat transfer oil 14 is circulated between the device 6 and the heat exchanger 10. At this time, the heat transfer oil 14 is discharged from the supply pipe 18 into the latent heat storage material layer 16, and the heat transfer oil 14 rises in the latent heat storage material layer 16 due to the specific gravity difference with the latent heat storage material 13, and the rise. In the process, heat is received in direct contact with the latent heat storage material 13.

  In this heat storage device 6, the solid-phase latent heat storage material 13 in the region 22 through which the heat transfer oil 14 does not pass passes along the inclined inner surface 23 of the heat storage tank 12 through the heat transfer oil 14 in the latent heat storage material layer 16. The solid-phase latent heat storage material 13 that easily slides down to the region 21 to be melted in direct contact with the heat transfer oil 14 and melts in a short time. Therefore, the heat storage device 6 can store heat in the latent heat storage material 13 in the region 22 where the heat transfer oil 14 does not pass in a short time without waste.

  In the above embodiment, the low friction coating 24 is applied to the entire inner surface of the heat storage tank 12, but the low friction coating 24 is at least in the region 22 where the heat transfer oil 14 does not pass among the inner surface of the heat storage tank 12. The phase latent heat storage material 13 may be applied to the inclined portion so as to slide down to the region 21 through which the heat transfer oil 14 passes.

  In the above embodiment, the low friction film 24 is formed on the inclined inner surface 23 in order to reduce the friction with the solid phase latent heat storage material 13, but even if a polished surface is formed instead of the low friction film 24. Good. Even in this case, the solid phase latent heat storage material 13 in the region 22 through which the heat transfer oil 14 does not pass passes along the polished surface to the region 21 through which the heat transfer oil 14 passes in the latent heat storage material layer 16. It becomes easy to slip off.

  Further, instead of forming the low friction film 24 on the inclined inner surface 23, a flow path 25 for heat source fluid (hot water, steam, etc.) may be provided along the outer surface of the heat storage tank 12, as shown in FIG. In this way, when storing heat in the heat storage device 6, the inclined inner surface 23 of the heat storage tank 12 can be heated by flowing a heat source fluid having waste heat of the heat source facility 1 through the flow path 25, and the inclination thereof. The liquid phase latent heat storage material melted along the inner surface 23 is interposed between the solid phase latent heat storage material 13 and the inclined inner surface 23, so that the solid phase latent heat storage material 13 and the inclined inner surface 23 are interposed. Friction can be reduced.

  On the other hand, when extracting heat from the heat storage device 6, if the solid phase latent heat storage material 13 in the region 22 through which the heat transfer oil 14 does not pass slides down to the region 21 through which the heat transfer oil 14 passes, the latent heat storage material 13. , The discharge of the heat transfer oil 14 from the supply pipe 18 may be hindered. Therefore, when extracting heat from the heat storage device 6, the heat source fluid is not passed through the flow path 25, thereby ensuring a frictional force between the inclined inner surface 23 and the solid phase latent heat storage material 13. Prevent sliding down.

  In the above embodiment, the shape of the heat storage tank 12 has been described by taking as an example the case where the central axis is a substantially horizontal cylindrical shape and the cross section perpendicular to the central axis is circular. It can also be applied to a heat storage tank having an elliptical cross section orthogonal to the polygonal shape, and a polygonal heat storage tank having a cross section orthogonal to the central axis narrowed at the bottom. The point is that the shape of the heat storage tank passes through the solid phase latent heat storage material 13 in the region 22 where the heat transfer medium oil 14 in the latent heat storage material layer 16 does not pass through the heat transfer medium oil 14 in the latent heat storage material layer 16. Any shape having an inclined inner surface 23 inclined so as to slide into the region 21 may be used.

  The said embodiment is an example of embodiment of this invention, and the technical scope of this invention is not limited to the said embodiment. The technical scope of the present invention is defined by the claims, and includes the meaning equivalent to the description of the claims and all modifications within the scope.

The figure which shows the heat transfer system using the heat storage apparatus of embodiment of this invention Sectional view of the heat storage device shown in FIG. Sectional view along line III-III in FIG. Sectional drawing which shows the modification of the heat storage apparatus of FIG. Sectional view showing a conventional heat storage device

Explanation of symbols

6 heat storage device 12 heat storage tank 13 latent heat storage material 14 heat medium oil 16 latent heat storage material layer 17 heat medium oil layer 18 supply pipe 19 recovery pipe 21 area through which heat medium oil passes 22 area through which heat medium oil does not pass 23 inclined inner surface 24 low Friction coating 25

Claims (7)

  A heat storage tank (12) for accommodating the latent heat storage material (13) and the heat transfer oil (14) having a specific gravity smaller than that of the latent heat storage material (13) in a state where the latent heat storage material (13) is separated into upper and lower layers, and the heat storage tank (12) The heat transfer oil (14) is recovered from the supply pipe (18) for supplying the heat transfer oil (14) into the latent heat storage material layer (16) and the heat transfer oil layer (17) in the heat storage tank (12). The heat transfer oil (14) supplied from the supply pipe (18) into the latent heat storage material layer (16) is brought into direct contact with the latent heat storage material (13) for heat exchange. In the heat storage device (6), the solid-phase latent heat storage material (in the region (22) where the heat transfer oil (14) does not pass through the latent heat storage material layer (16) has a shape of the heat storage tank (12). 13) inclined inner surface (23 inclined to slide down to the region (21) through which the heat transfer oil (14) passes. The a shape with, its inclined inner surface (23), thermal storage, characterized in that a friction reducing means for reducing friction between the solid phase latent heat storage material (13) (24) device.   The heat storage device according to claim 1, wherein the friction reducing means is a low friction film (24) formed on the inclined inner surface (23).   The heat storage device according to claim 1, wherein the friction reducing means is a polished surface formed on the inclined inner surface (23).   The heat storage device according to claim 1, wherein the friction reducing means is a heating mechanism (25) for heating the inclined inner surface (23).   The heat storage device according to claim 4, wherein the heating mechanism is a flow path (25) of a heat source fluid provided along an outer surface of the heat storage tank (12).   The heat storage device according to claim 4 or 5, wherein heating by the heating mechanism (25) can be released.   The shape of the heat storage tank (12) is a cylindrical shape whose central axis is substantially horizontal, and a cross section perpendicular to the central axis is circular, elliptical, or a polygon whose bottom is narrowed. The thermal storage apparatus in any one of.

Images