JP4422702B2 - Heat storage method for heat storage device - Google Patents

Description

  The present invention relates to a heat storage method for a heat storage device that can effectively use waste heat of a heat generation facility such as a waste incinerator, particularly sensible heat of exhaust gas to transport heat to a remote use place.

  As a heat storage device that temporarily stores heat generated by a heat source, one disclosed in Patent Document 1 is known. In the heat storage device of Patent Document 1, a heat storage material that stores latent heat and a heat medium that has a specific gravity smaller than that of the heat storage material and separates from the heat storage material are housed in the heat storage container. The heat storage container is separated from the heat medium in the upper part and the heat storage material in the lower part due to the difference in specific gravity. When a heat medium supplied with heat from a heat source (for example, solar heat, factory waste liquid, nighttime electric power, etc.) is supplied from the bottom of the heat storage container, the heat medium moves to the top of the heat storage container because the specific gravity is smaller than that of the heat storage material. . And by making direct contact with the heat storage material during this movement, the heat supplied to the heat medium is transmitted to the heat storage material and stored.

  Moreover, when utilizing the heat | fever stored, when a heat medium is supplied from the bottom part of a thermal storage container, since specific gravity is smaller than a thermal storage material, it moves to the upper part of a thermal storage container. And by making direct contact with the heat storage material during this movement, the heat stored in the heat storage material is transferred to the heat medium, and heat is supplied to the heat medium. Then, by supplying this heat medium to the heat extractor and recovering heat by the heat extractor, for example, heat can be used in an external device such as a heating device.

By the way, in a waste incineration facility, a waste heat boiler is generally installed in order to effectively recover and use sensible heat of combustion exhaust gas after waste incineration. The high-temperature combustion exhaust gas from the waste incinerator (facility) is usually cooled to a temperature range of about 200 to 400 ° C. by heat exchange in the waste heat boiler. It is desirable to reuse the flue gas without throwing it away from the chimney. In addition, in small-scale waste treatment facilities such as those installed in local cities with a small population, the installation of the waste heat boiler is omitted. The present situation is that most of the sensible heat of the exhaust gas is discarded by cooling, and the sensible heat of the exhaust gas is more effectively used .
JP 58-104494 A

An object of the present invention is taken up heat storage transport as an active usage of the heat, waste heat of the heat generating facility, such as waste incinerators, particularly by effectively utilizing the waste gas scan of sensible heat, the remote use location It is providing the thermal storage method to the thermal storage apparatus which can convey heat.

  In order to solve the above problems, the present invention employs the following configuration.

That is, a heat storage method for a heat storage device according to claim 1 includes a heat storage body that stores heat using a state change between a solid and a liquid, and a heat exchange medium that exchanges heat with the heat storage body to cause the state change. A heat storage method comprising a storage container provided with a supply flow path and a discharge flow path for the heat exchange medium, and capable of heat transport , wherein combustion exhaust gas from a waste incinerator is transferred to a dust collector The exhaust gas is heated to a temperature range of 170 to 300 ° C. and passed through the catalytic reaction tower, and the heat storage medium is heat-exchanged with the fluid preheated with the exhaust gas. After heating above the melting temperature, the heat exchange medium is supplied to the storage container, and the heat storage body is melted to store heat.

In general, by exchanging heat between the combustion exhaust gas and the heat exchange medium, the heat exchange medium can be heated to a temperature range suitable for the state change of the heat storage body, and the sensible heat (sensible heat) of the exhaust gas can be effectively used. Can do. Note that air is optimal as the fluid for exchanging heat with the exhaust gas, but oil or water can also be used.
Since the temperature of the exhaust gas is usually lowered to about 150 to 200 ° C. after exchanging heat with the fluid for heating the heat exchange medium, dust in the exhaust gas can be collected by a dust collector such as a filtration dust collector. it can. At that time, acid components such as HCl and SO _X contained in the exhaust gas are also removed. Further, since the nitrogen oxides in the exhaust gas can also be removed in the catalytic reaction tower, corrosion of the heat exchanger can be prevented during heat exchange with air or fluid such as oil or water that heats the heat exchange medium. Further, in order to increase the activity of the catalyst in the catalytic reaction tower, it is necessary to reheat the exhaust gas lowered to 150 to 200 ° C. again to 170 to 300 ° C., but the exhaust gas exiting the reheated catalyst reaction tower is By storing heat in a heat storage device capable of heat transport, the sensible heat of the reheated exhaust gas can be recovered and used effectively.

The heat storage method for the heat storage device according to claim 2 is such that the heat exchange medium has a smaller specific gravity than the heat storage body and does not separate and mix with the heat storage body due to a difference in specific gravity, and directly contacts the heat storage body. It is characterized by exchanging heat.

  Thus, according to the direct contact, the heat storage body can be efficiently heated and melted, and the heat storage time can be shortened compared with the case of indirect heating. In addition, as such a heat exchange medium, a nonflammable machine oil can be mentioned, for example.

The heat storage method for a heat device according to claim 3 is characterized in that the heat storage body is erythritol.

  Erythritol is widely used as an artificial sweetening amount, has a large latent heat of fusion, and has a high melting point of about 120 ° C., so that it can be suitably used as a highly safe heat storage material.

The heat storage method of the heat storage apparatus according to claim 4 is characterized in that the temperature of the heat exchange medium supplied to the heat storage body is in a range of 120 to 180 ° C.

  When erythritol is used as the heat storage body, if the temperature of the heat exchange medium to be supplied is lower than 120 ° C, the heating / melting time of the heat storage body becomes longer, and if it exceeds 180 ° C, heat is supplied to the heat storage body. Even after the heat storage, it is in a high-temperature state that is higher than the melting temperature range of the heat storage body, which may hinder the state change from melting to solidification of the heat storage body. In either case, efficient heat storage transport cannot be performed in a short time. .

The heat storage method of the heat storage device according to claim 5 is characterized in that the heat storage body is a sugar alcohol.

According to the heat storage method of the heat storage device of the present invention, effective utilization of combustion flue gas sensible heat of waste incinerators, as heat accumulating heat source to the heat storage device capable of transporting heat to the heat demand away be able to. As a result, the sensible heat discharged from the waste incinerator can be used more effectively, and heat can be supplied to the heat demand facility around the waste incineration facility with a simple device. It is possible to reduce the amount of global warming effect gas generation such as CO ₂ in the country.

It will be described below with reference to embodiments of the present invention from the attached Figure 1 in Figure 4.

Figure 1 is a diagram illustrating a flow (flow) of the heat storage process to thermal storage device. The combustion exhaust gas from the waste incinerator 1 is supplied to one flow path of the air preheating heat exchanger 3. The air preheating heat exchanger 3 preheats heat exchanging air for raising the temperature of a heat exchanging medium that exchanges heat with a heat storage body to a required temperature range. It is supplied to the other flow path of the exchanger 3 and preheated to a temperature range of about 100 to 200 ° C. The heat exchange air is supplied to one flow path of the heat storage heat exchanger 4, discharged from the heat storage device 5, and exchanges heat with the heat exchange medium supplied from the other flow path. When the medium uses erythritol having a melting temperature of about 119 ° C. as a required temperature range, for example, as a heat storage body, the medium is heated to about 120 to 180 ° C. and supplied to the heat storage device 5. After the heat exchange, the exhaust gas discharged from the air preheating heat exchanger 3 is cooled to a predetermined temperature, and then sent to the dust collector 6 to remove soot and acidic components in the gas. Instead of the heat storage method shown in FIG. 1, the heat exchange medium discharged from the heat storage device 5 is supplied to the other flow path of the air preheat heat exchanger 3 without using the preheat air. By directly exchanging the heat exchange medium with the exhaust gas, when using erythritol having a melting temperature of about 119 ° C. as a heat storage body, the heat storage device is heated to about 120 to 180 ° C. 5 may be supplied.

  In a small-scale waste treatment facility such as a small-scale waste disposal facility installed in a small population, the waste heat boiler 2 is often not installed. Therefore, the air preheating heat exchanger 3 includes the waste incinerator 1 and the dust collector 6. It is installed somewhere in between. Further, as the processing scale of the waste treatment facility increases, as shown by the broken line in FIG. 1, the waste heat boiler 2 is often installed. In this case, the heat exchange for air preheating is performed. The vessel 3 is installed on the rear stage side of the waste heat boiler 2.

  FIG. 2 shows a heat storage device 5 and a heat storage heat exchanger 4 (see FIG. 1). This heat storage device 5 stores oil 9 as a heat exchange medium and erythritol 10 as a heat storage body. A container 5a, a supply pipe 11 for oil 9, and a discharge pipe 12 are provided. The oil 9 and the erythritol 10 contained in the storage container 5a are not mixed with each other, and the oil 9 has a specific gravity smaller than that of the erythritol 10, so that the oil 9 is separated into the upper layer and the erythritol 10 is separated into the lower layer in the storage container 5a. To be housed. The supply pipe 11 and the discharge pipe 12 have respective connection ports 11a and 12a detachably connected to the connection pipes 13 and 13 of the heat storage heat exchanger 4. Then, the pump 14 interposed in the discharge pipe 12 is operated, so that the oil 9 circulates through the supply pipe 11 and the discharge pipe 12 and circulates between the storage container 5a and the heat storage heat exchanger 4. ing. A thermometer 15 is provided on the inlet side of the storage container 5a of the supply pipe 11, and the supply amount of the oil 9 is controlled based on the measured value of the temperature of the oil 9 supplied into the storage container 5a. ing.

  The heat exchange medium oil 6 heated to about 130 to 180 ° C. in the heat storage heat exchanger 4 is discharged in a plurality of downward directions in a supply pipe 11 disposed horizontally in the lower layer portion of the storage container 5a. It is supplied into erythritol 10 through a hole (not shown). Since the heat exchange medium oil 9 has a specific gravity smaller than that of erythritol 10, it rises to the upper oil 9 and is taken into the upper oil 9. During this rise, heat exchange takes place between the oil 9 and erythritol 10 by direct contact. Erythritol 10 has a melting point of about 119 ° C. and is in a solid state at room temperature, but heat is conducted by direct contact from oil 9 heated to about 120 to 180 ° C. supplied from heat storage heat exchanger 4. The temperature is raised, the heat of fusion is absorbed, the state changes from solid to liquid, and heat is stored in the liquid state. The heat storage device 5 is not necessarily limited to a system in which the heat exchange medium (oil 9) and the heat storage body (erythritol 10) exchange heat by direct contact, and a heat exchange medium supplied from the heat storage heat exchanger 4 is used. It is also possible to adopt a system in which heat is stored in the liquid state by circulating the heat transfer tube disposed in the storage container 5a and heating the heat storage body by indirect contact.

  Next, a method for transporting heat stored in the heat storage device 5 will be described. As shown in FIG. 3, the heat storage device 5 includes a garbage incineration facility 17 including the waste incinerator 1 shown in the heat storage flow of FIG. Are being transported between. The heat demand facility 18 is an agricultural / fishery facility (glass greenhouse (cooling / heating), aquaculture aquarium (heating)), or a large local facility (hospital, school, heated pool, etc.) for hot water supply / cooling. On the heat demand facility 18 side, heat is extracted from the erythritol 10 that is stored in a liquid state as follows. The supply pipe 11 and the discharge pipe 12 of the heat storage device 5 shown in FIG. 2 are detachably connected to the respective connection ports of the heat supply heat exchanger 19 on the heat demand facility 18 side, and further, heat exchange for heat supply. A pipe (not shown) for taking fluid from a temperature control facility such as a heat pump of the heat demand facility 18 and a pipe (not shown) for supplying the heated fluid to the temperature control facility are connected to the vessel 19. . Then, the pump 14 of the heat storage device 5 is operated, and the oil 9 in the upper layer of the heat storage device 5 is taken into the heat supply heat exchanger 19 from the discharge pipe 12, and this taken-in oil 9 is supplied from the supply pipe 11 to the liquid It is supplied into erythritol 10 which is stored in a state. The supplied oil 9 is in direct contact with the erythritol 10 while rising, and heat is conducted from the erythritol 10. As a result, heat is supplied to the upper oil layer 9, and the oil 9 whose temperature has risen is taken into the heat exchanger 19 for supplying heat from the discharge pipe 12 as described above. The solidification latent heat released by the erythritol 10 in the state is taken out, and the solidification of the erythritol 10 proceeds from the liquid state with the release of the solidification latent heat. The extracted heat is conducted to the heat supply heat exchanger 19 by the fluid taken in from the temperature control equipment on the heat demand facility side, and the fluid whose temperature has been increased by heat exchange is supplied to the temperature control equipment. Thus, the heat stored in the heat storage device 5 that has been transported from the waste incineration facility by the truck 16 or the like passes through the heat exchanger 19 for heat supply, and is used in a cooling / heating device or a water heater in the heat demand facility 18. Supplied to the temperature control equipment.

4 (a) and 4 (b) show a flow of a heat storage method to the heat storage device of the embodiment according to the present invention . As shown in FIG. 1, the exhaust gas that has passed through the air preheating heat exchanger 3 is sent to a dust collector 6 where dust, acid components, and the like in the exhaust gas are removed and released from the chimney to the atmosphere. As shown in FIG. 4A, the exhaust gas from which dust and acid components have been removed by the dust collector 6 is heated to a temperature of 170 to 300 ° C. by a heater 7 using a waste heat boiler steam or an electric heater as a heat source. After being heated to the zone, nitrogen oxides are removed in the catalytic reaction tower 8. The clean exhaust gas from which dust, acidic components, and nitrogen oxides are removed is supplied to one flow path of the heat storage heat exchanger 4a. A heat exchange medium discharged from the heat storage device 5 is supplied to the other flow path of the heat storage heat exchanger 4a, and the heat exchange medium exchanges heat with the exhaust gas to obtain a required temperature range, for example, heat storage. When erythritol having a melting temperature of about 119 ° C. is used as a body, it is heated to about 120 to 180 ° C. and supplied to the heat storage device 5. Since the dust and acid components are removed from the exhaust gas after passing through the dust collector 6, corrosion of the heat storage heat exchanger 4a is prevented, and the sensible heat of the low-temperature exhaust gas can be used more effectively. Instead of directly exchanging heat between the exhaust gas and the heat exchange medium, as shown in FIG. 4B, heat exchange air preheated by heat exchange with the exhaust gas using the air preheater 3a is used for heat storage. Heating the heat exchange medium to a required temperature range by supplying the heat exchange medium supplied to one flow path of the heat exchanger 4a and supplying the heat exchange medium discharged from the heat storage device 5 to the other flow path for heat exchange. You can also.

  As the incinerator 1, various incinerators such as a stoker furnace, a fluidized bed furnace, and a kiln furnace are applied, and the ash content in the garbage is melted by the heat generated by burning the combustible gas after gasifying the garbage. Kiln type, fluidized bed type, and shaft type gasification and melting furnaces are also applicable. An ash melting furnace that melts incineration residue with an external heat source such as fossil fuel or electricity is also applied.

In the above embodiment, erythritol 10 is used as a heat storage body. However, the heat storage body is not limited to this, and xylitol (C ₅ H ₁₂ O ₅ ), D-mannitol (C ₆ H ₁₄ O ₆ ), galactitol ( It goes without saying that sugar alcohols such as C ₆ H ₁₄ O ₆ ) can be used. In addition, the present invention is not limited to the waste incineration facility (general waste waste incineration facility) such as municipal waste, as the waste incineration facility to which the present invention is applied is described in the above embodiment. It can also be applied to incineration facilities for industrial waste such as sewage sludge, construction waste, shredder dust, coal scrap, and biomass waste.

It is an explanatory diagram showing a flow of the thermal storage method of the thermal storage device. It is explanatory drawing which shows an example of the thermal storage apparatus of FIG. It is explanatory drawing which shows typically the heat transport method using the thermal storage apparatus of FIG. (A) It is explanatory drawing which shows the flow of the thermal storage method to the thermal storage apparatus of embodiment concerning this invention . (B) Same as above

DESCRIPTION OF SYMBOLS 1 ... Waste incinerator 2 ... Waste heat boiler 3, 3a ... Air preheating heat exchanger 4, 4a ... Thermal storage heat exchanger 5 ... Thermal storage device 6 ... Dust collector 7 ..Heater 8 ... Catalytic reaction tower 9 ... Oil (heat exchange medium)
10 ... Erythritol (heat storage)
DESCRIPTION OF SYMBOLS 11 ... Supply pipe 12 ... Discharge pipe 11a, 12a ... Connection port 13 ... Connection pipe 14 ... Pump 15 ... Thermometer 16 ... Truck 17 ... Waste incineration plant 18 ... heat demand facility 19 ... heat supply heat exchanger

Claims (5)

A heat accumulator that stores heat using a change in state between a solid and a liquid, and a heat exchange medium that exchanges heat with the heat accumulator to cause the change in state are accommodated, and a supply flow path and an exhaust flow of the heat exchange medium A heat storage method for a heat storage device comprising a storage container provided with a passage and capable of heat transport, wherein the exhaust gas from the waste incinerator is collected by a dust collector, and then in a temperature range of 170 to 300 ° C. Exhaust gas after being heated and passing through the catalytic reaction tower, the heat exchange medium is heat-exchanged with the fluid preheated with the exhaust gas and heated above the melting temperature of the heat storage body, and then the heat exchange medium is A heat storage method for a heat storage device, wherein the heat storage device is supplied to a storage container and melts and stores heat. Said heat exchange medium, which does not mix separated by the heat storage medium and the specific gravity difference even small specific gravity than the heat storage body, claim 1, characterized in that the heat exchange by direct contact with the heat storage body The heat storage method to the heat storage apparatus as described in 2. Thermal storage method of the heat storage device according to claim 1 or 2, wherein the heat storage body is erythritol. The method for storing heat in a heat storage device according to claim 3 , wherein when the heat storage body stores heat, a temperature of a heat exchange medium supplied to the storage container is in a range of 120 to 180 ° C. The heat storage method for a heat storage device according to claim 1 or 2 , wherein the heat storage body is a sugar alcohol.

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