JP6818942B1 - Heat storage type water heater - Google Patents

Abstract

The heat storage type water heater is housed in the container, the heat storage material filled inside the container, and the heat exchange with the first heat medium to store heat in the heat storage material, and also with the second heat medium. It is equipped with a heat exchanger that exchanges heat and dissipates heat from the heat storage material. The heat storage material has erythritol and water. The mixing ratio of erythritol to water is 60 [wt%] or more and 80 [wt%] or less by weight.

Description

The present invention relates to a heat storage type water heater provided with a heat storage material having erythritol and water.

Conventionally, a heat storage type water heater using a heat storage material is known. Water is generally used as the heat storage material of the heat storage type water heater, but a latent heat storage material that utilizes the latent heat when the phase changes from a solid to a liquid having a large amount of heat storage per volume is also used. For example, Patent Document 1 discloses a configuration using erythritol, which is a kind of sugar alcohol, as a heat storage material for a heat storage type water heater.

Japanese Unexamined Patent Publication No. 2000-087020

Erythritol is widely used as a heat storage material because it has a larger amount of latent heat than other types of latent heat storage materials and has a high melting point of 119 ° C. when releasing the latent heat. However, when erythritol is used as a heat storage material in system equipment such as water heaters used at 100 ° C or lower, such as hot water supply, the latent heat of erythritol may be sufficiently released during a phase change due to the high melting point of erythritol. This may not be possible and the amount of heat storage may decrease. Therefore, when erythritol is used as a heat storage material in a system device such as a water heater, it is necessary to fill the container with a heat storage material sufficient to obtain a sufficient amount of heat storage, which may increase the size of the device.

The present invention has been made to solve the above problems, and heat storage is performed even when a heat storage material containing erythritol as a main component is used for a system device used at 100 ° C or lower such as a hot water supply. It is an object of the present invention to provide a heat storage type water heater that can realize miniaturization as a whole by suppressing a decrease in the amount.

In the heat storage type water heater according to the present invention, a container in which heat exchange is performed, a heat storage material filled in the container, and a heat storage material contained in the container are housed in the container and exchange heat with a first heat medium. The heat storage material includes a heat exchanger that stores heat in the heat storage material and exchanges heat with a second heat medium to dissipate heat from the heat storage material, and a device for flowing the heat storage material. The heat storage material includes erythritol and the erythritol. The mixing ratio of the erythritol to the water is 60 [wt%] or more and 80 [wt%] or less by weight, and the heat storage material is such that the erythritol is precipitated at the time of heat dissipation. The solid phase portion and the aqueous solution portion in which the solid phase of the erythritol is not precipitated are separated, the heat storage material is flowed by a device for flowing the heat storage material, and the solid phase portion is deposited on the lower part of the container. , The aqueous solution portion is located above the solid phase portion .

According to the present invention, since a heat storage material having erythritol and water and having a mixing ratio of erythritol to water having a weight ratio of 60 [wt%] or more and 80 [wt%] or less is used, erythritol is dissolved in water. By doing so, the temperature (melting point) at which erythritol changes in phase can be lowered to 60 ° C. to 90 ° C., which is suitable for use in the range of 40 ° C. to 90 ° C. for hot water supply. As a result, the latent heat of erythritol can be sufficiently released, and the amount of heat stored in the heat storage material can be improved. Therefore, even when a heat storage material containing erythritol as a main component is used for a system device used at 100 ° C. or lower such as a hot water supply, the heat storage amount of the heat storage material can be improved, so that the heat storage material to be filled in the container can be improved. By reducing the amount of material, it is possible to realize miniaturization as a whole.

It is a schematic diagram which shows the internal structure of the state at the time of heat dissipation of the heat storage material which is the heat storage type water heater which concerns on Embodiment 1. FIG. It is a graph which showed the relationship between the mixing ratio of erythritol with respect to water, and the melting point of a heat storage material. It is a graph which showed the relationship between the mixing ratio of erythritol with respect to water, and the amount of heat per unit area of a heat storage material. It is a schematic diagram which showed the modification of the heat storage type water heater which concerns on Embodiment 1. FIG. It is a schematic diagram which shows the internal structure of the state at the time of heat dissipation of the heat storage material which is the heat storage type water heater which concerns on Embodiment 2.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each figure, the same or corresponding parts are designated by the same reference numerals, and the description thereof will be omitted or simplified as appropriate. In addition, the shape, size, arrangement, etc. of the configurations shown in each figure can be appropriately changed within the scope of the present invention.

Embodiment 1.
(Structure of heat storage type water heater 100)
FIG. 1 is a schematic view showing the internal configuration of the heat storage type water heater according to the first embodiment and the state of the heat storage material at the time of heat dissipation. As shown in FIG. 1, the heat storage type water heater 100 according to the first embodiment exchanges heat with the container 1, the heat storage material 2, and the first heat medium to store heat in the heat storage material 2, and the second It is provided with a heat exchanger 3 that exchanges heat with the heat medium of the above and dissipates heat from the heat storage material 2, and a stirrer 6 that stirs the heat storage material 2.

The container 1 has, for example, a substantially rectangular parallelepiped shape. The material of the container 1 is a material having high heat resistance and strength such as SUS, Al, Cu or polycarbonate. Inside the container 1, a heat storage material 2, a heat exchanger 3, and a stirring blade 60 of a stirrer 6 are housed. A plurality of openings into which the hot water supply water inflow pipe 4b, the hot water supply water outflow pipe 4c, the heat medium inflow pipe 5b, and the heat medium outflow pipe 5c of the heat exchanger 3 are inserted are formed on the side surface of the container 1. The lower part of the container 1 serves as a deposition space for depositing the solid of erythritol 20 that precipitates on the inner bottom surface of the container 1 when the heat storage material 2 dissipates heat.

The heat storage material 2 mainly contains erythritol 20 and water 21. The erythritol 20 includes erythritol, pentaerythritol, dipentaerythritol and the like. The water 21 is preferably pure water, but it does not have to be pure water as long as it does not contain a substance that deteriorates erythritol 20. Erythritol 20 and water 21 have the property of dissolving and have a high heat storage amount. In the heat storage type water heater 100, since the heat storage material 2 has a high heat storage amount, the filling amount of the heat storage material 2 to be filled in the container 1 can be reduced, and the size can be reduced as a whole. Further, the heat storage material 2 becomes an aqueous solution in which the solid phase of erythritol 20 is not precipitated as a whole during heat storage, and as shown in FIG. 1, the solid phase portion B in which erythritol 20 is precipitated and erythritol during heat dissipation are used. It has the property of separating the solid phase of 20 into the aqueous solution part A in which it is not precipitated.

The heat exchanger 3 includes a heat exchanger 4 for heat dissipation and a heat exchanger 5 for heat storage. The heat radiating heat exchanger 4 is, for example, a tube-type heat exchanger, and has a heat radiating heat transfer pipe 4a, a hot water supply water inflow pipe 4b, a hot water supply water outflow pipe 4c, and fins 4d. Further, the heat storage heat exchanger 5 is, for example, a tube type heat exchanger, and has a heat storage heat transfer tube 5a, a heat medium inflow pipe 5b, a heat medium outflow pipe 5c, and fins (not shown). There is.

The heat transfer tube 4a for heat dissipation is cylindrical, flat plate or flat. The heat dissipation tube 4a is formed by processing a metal such as aluminum, Cu, or SUS. Hot water supply flows inside the heat radiating heat transfer tube 4a as a second heat medium for releasing the heat of the heat storage material 2.

The hot water supply water inflow pipe 4b and the hot water supply water outflow pipe 4c are formed by processing a metal such as aluminum, Cu, or SUS. The hot water supply water inflow pipe 4b is inserted into an opening formed on one side surface of the container 1 and is provided straddling the inside and the outside of the container 1, and the end inside the container is at one end of the heat dissipation tube 4a for heat dissipation. It is connected. The hot water supply water outflow pipe 4c is inserted into an opening formed on one side surface of the container 1 and is provided so as to straddle the inside and the outside of the container 1, and the end inside the container is the other end of the heat transfer tube 4a for heat dissipation. It is connected to the. In the heat storage type water heater 100 according to the first embodiment, the hot water supply water inflow pipe 4b is arranged above the container 1, and the hot water supply water outflow pipe 4c is arranged below the container 1. However, the hot water supply water inflow pipe 4b may be arranged below the container 1, and the hot water supply water outflow pipe 4c may be arranged above the container 1.

The fin 4d is made by processing a metal having high thermal conductivity such as aluminum, Cu, SUS, or carbon into a flat plate shape. The fins 4d are provided on the outer peripheral surface of the heat dissipation tube 4a.

The heat storage tube 5a is cylindrical, flat or flat. The heat storage tube 5a is formed by processing a metal such as aluminum, Cu, or SUS. An HFC-based refrigerant such as water, oil, carbon dioxide, or R410a flows inside the heat storage tube 5a as a first heat medium for heating the heat storage material 2.

The heat medium inflow pipe 5b and the heat medium outflow pipe 5c are formed by processing a metal such as aluminum, Cu, or SUS. The heat medium inflow pipe 5b is inserted into an opening formed on one side surface of the container 1 and is provided so as to straddle the inside and the outside of the container 1, and the end inside the container is at one end of the heat storage tube 5a. It is connected. The heat medium outflow pipe 5c is inserted into an opening formed on one side surface of the container 1 and is provided straddling the inside and the outside of the container 1, and the end inside the container is the other end of the heat storage tube 5a for heat storage. It is connected to the. In the heat storage type water heater 100 according to the first embodiment, the heat medium inflow pipe 5b is arranged above the container 1, and the heat medium outflow pipe 5c is arranged below the container 1. However, the heat medium inflow pipe 5b may be arranged below the container 1, and the heat medium outflow pipe 5c may be arranged above the container 1.

The fins of the heat storage heat exchanger 5 are made by processing a metal having high thermal conductivity such as aluminum, Cu, SUS, or carbon into a flat plate shape. The fins of the heat storage heat exchanger 5 are provided on the outer peripheral surface of the heat storage heat transfer tube 5a.

The heat radiating heat exchanger 4 may be provided as long as it has a structure capable of radiating heat from the heat storage material 2, and its shape may be appropriately changed according to the implementation situation. For example, the heat radiating heat exchanger 4 may not have fins 4d and may be composed of only the heat radiating heat transfer pipe 4a, the hot water supply water inflow pipe 4b, and the hot water supply water outflow pipe 4c.

Similarly, the heat storage heat exchanger 5 may be provided as long as it has a structure capable of storing heat in the heat storage material 2, and its shape is appropriately changed according to the implementation situation. For example, the heat storage heat exchanger 5 may not have fins and may be composed of only the heat storage heat transfer pipe 5a, the heat medium inflow pipe 5b, and the heat medium outflow pipe 5c.

Further, although the tube type heat exchanger has been described as an example of the heat dissipation heat exchanger 4 and the heat storage heat exchanger 5, a plurality of flat plates are laminated as long as the heat exchange is possible with the heat storage material 2. A plate type heat exchanger may also be used.

The stirrer 6 has a stirring blade 60 for stirring the heat storage material 2 and a rotating machine 61 for rotating the stirring blade 60. The stirring blade 60 is made of a metal material such as SUS, aluminum or Cu, a lightweight material such as plastic or resin, or a magnetic material such as a magnet. The stirring blade 60 is rotated by the drive of the rotating machine 61 to stir the heat storage material 2. The rotary machine 61 is a drive source for rotating the stirring blade 60 by, for example, an electrically driven motor or a magnetic field.

(Mixing ratio of erythritol 20 and water 21)
Next, the mixing ratio of erythritol 20 and water 21 will be described with reference to FIGS. 2 and 3. FIG. 2 is a graph showing the relationship between the mixing ratio of erythritol with respect to water and the melting point of the heat storage material. In FIG. 2, the horizontal axis represents the mixing ratio [wt%] of erythritol 20 to water 21, and the vertical axis represents the melting point [° C.] of the heat storage material 2. Erythritol 20 has the property of being soluble in water 21. The heat storage material 2 can lower the temperature (melting point) at which erythritol 20 undergoes a phase change by dissolving erythritol 20 in water 21. As shown in FIG. 2, the heat storage material 2 has a property that the melting point decreases as the mixing ratio of erythritol 20 with respect to water 21 decreases. When the heat storage material 2 is used in the range of 40 ° C. to 90 ° C. for hot water supply, the melting point is preferably in the range of 60 ° C. to 90 ° C. Then, from FIG. 2, the mixing ratio of erythritol 20 to water 21 is preferably 60 [wt%] or more and 80 [wt%] or less by weight.

Next, FIG. 3 is a graph showing the relationship between the mixing ratio of erythritol with respect to water and the amount of heat per unit area of the heat storage material. In FIG. 3, the horizontal axis shows the mixing ratio [wt%] of erythritol 20 to water 21, and the vertical axis shows the amount of heat [MJ · L ^-1 ] per unit volume of the heat storage material 2. As shown in FIG. 3, the amount of heat per unit volume of the heat storage material 2 increases according to the mixing ratio of erythritol 20, and the mixing ratio of erythritol 20 becomes maximum at around 80 [wt%] by weight. That is, the optimum mixing ratio of erythritol 20 is around 80 [wt%] by weight. Therefore, from the results of FIGS. 2 and 3, when used in the range of 40 ° C. to 90 ° C. for hot water supply, the mixing ratio of erythritol 20 to water 21 is 60 [wt%] or more and 80 [wt%] or less by weight. It becomes suitable, and more specifically, a weight ratio of 80 [wt%] is optimal.

(Heat storage operation of heat storage type water heater 100)
Next, the heat storage operation of the heat storage type water heater 100 will be described. In the heat storage type water heater 100, when a high-temperature heat medium flows from the heat medium inflow pipe 5b of the heat storage heat exchanger 5, heat is transferred from the heat storage heat transfer tube 5a to the heat storage material 2 via fins. In the heat storage type water heater 100, when the low temperature heat storage material 2 is warmed and the temperature rises to reach the melting point, the solid phase of erythritol 20 melts and becomes a liquid phase. On the other hand, the temperature of the heat medium that gives heat to the heat storage material 2 drops, and the heat medium is discharged from the heat medium outflow pipe 5c. Further, at the time of heat storage, the heat storage material 2 can be stirred by rotating the stirring blade 60 of the stirrer 6. By stirring the heat storage material 2, the heat exchange performance between the heat storage material 2 and the heat medium is improved. Here, the heat source machine for heating the heat medium flowing through the heat storage heat exchanger 5 may be a heat pump, a heater, or a combustor, as long as it can heat the heat medium. Further, the system for heating the heat medium is a circulation type system in which the heat medium is discharged from the heat medium outflow pipe 5c, flows through the heat source machine, and flows into the heat storage heat exchanger 5 again from the heat medium inflow pipe 5b. It may be a transient type that is discharged from 5c to the outside and does not circulate.

(Heat dissipation operation of heat storage type water heater 100)
Next, the heat dissipation operation of the heat storage type water heater 100 will be described. In the heat storage type water heater 100, when the hot water supply water flows from the hot water supply water inflow pipe 4b of the heat dissipation heat exchanger 4, the heat of the heat storage material 2 is transmitted to the heat dissipation tube 4a via the fins 4d, and the hot water supply flows inside. The temperature of the water rises. At the same time, the heat storage material 2 is deprived of heat and its temperature drops. Then, the temperature of the heat storage material 2 around the heat radiating heat transfer tube 4a reaches the melting point, and a solid phase of erythritol 20 is deposited around the heat radiating heat transfer tube 4a. The hot water supply water to which heat is applied from the heat storage material 2 and the temperature rises is discharged from the hot water supply water outflow pipe 4c. Further, the heat storage material 2 can be agitated by rotating the agitating blade 60 of the agitator 6 at the time of heat dissipation. The solid phase of erythritol 20 has a lower thermal conductivity than substances such as metals. Therefore, in the heat storage type water heater 100, the heat exchange performance between the heat storage material 2 and the heat medium can be improved by rotating the stirrer 6 to stir the heat storage material 2.

(Arrangement position of stirring blade 60)
Next, the arrangement position of the stirring blade 60 will be described. The heat storage material 2 is a mixed solution of erythritol 20 and water 21. The concentration of erythritol 20 in the heat storage material 2 is calculated by the formula (1) using the temperature of the heat storage material 2.
x = -0.00387T ² + 1.34T-5.94 (1)
x is the erythritol concentration [wt%] in the heat storage material 2. T is the temperature [° C.] of the heat storage material 2. That is, the solid phase amount of erythritol 20 precipitated from the heat storage material 2 and the liquid phase amount with the heat storage material 2 are uniquely determined according to the temperature of the heat storage material 2 at the time of heat dissipation. The solid phase amount of erythritol 20 precipitated from the heat storage material 2 according to the temperature of the heat storage material 2 at the time of heat dissipation can be obtained from the formula (1). Specifically, assuming that the size of the container (width W [mm] x depth B [mm] x height H [mm]) and the solid phase amount is V [mm3], the bottom area of the container 1 (width W). The height H'where the solid phase is deposited from [mm] x depth B [mm]) is H'= V / (B x W).

On the other hand, the stirring blade 60 of the stirrer 6 should be arranged in the aqueous solution portion A of the heat storage material 2. This is because the stirring blade 60 can stir the heat storage material 2 without causing a decrease in power due to the solid phase of the erythritol 20, so that stable heat exchange is possible and the hot water supply performance is improved.

Therefore, the heat storage type water heater 100 is based on the formula (1) and the solid phase amount of erythritol 20 calculated based on the temperature of the heat storage material 2 at the time of heat dissipation, and the solid phase portion B and the aqueous solution portion A at the time of heat dissipation. By arranging the stirring blade 60 of the stirrer 6 between the heights H'and more and H or less, which is the portion where the aqueous solution part A is located in the state where and is separated, stable heat exchange is possible. Become.

(Effect of providing the stirrer 6)
Next, the effect of the stirrer 6 for stirring the heat storage material 2 will be described. The heat storage material 2 is a mixed solution of erythritol 20 and water 21, and is characterized in that the erythritol 20 dissolves in water 21. For example, when a general heat storage material 2 such as paraffin, erythritol alone, or sodium acetate trihydrate is cooled by using a heat exchanger or the like, the temperature of the heat storage material 2 drops from the heat transfer surface, and the heat transfer surface The solid phase of the heat storage material 2 is deposited on the heat storage material 2. On the other hand, when the heat storage material 2 of the first embodiment is cooled, erythritol 20 precipitates from the water 21 and solidifies. Then, when the heat storage material 2 is cooled while flowing by the stirrer 6, the temperature of the heat storage material 2 becomes uniform, so that the erythritol 20 is solidified from the water 21 located away from the heat transfer surface. Since the solid phase of erythritol 20 solidified on a surface other than the heat transfer surface is higher than the density of the heat storage material 2, it is deposited in the lower part of the container 1. That is, in the heat storage type water heater 100 according to the first embodiment, the solid phase amount of erythritol 20 deposited on the surface of the heat exchanger 3 can be reduced by stirring the heat storage material 2 with the stirrer 6. Therefore, deterioration of the heat exchange performance of the heat exchanger 3 can be suppressed. That is, since the heat storage type water supply device 100 is provided with the stirrer 6, the heat exchange performance can be sufficiently exhibited even if the heat dissipation heat exchanger 4 and the heat storage heat exchanger 5 are miniaturized. The vessel 3 can be miniaturized to miniaturize the entire apparatus.

As described above, the heat storage type water heater 100 according to the first embodiment is housed in the container 1, the heat storage material 2 filled in the container 1, and the first heat medium. It is provided with a heat exchanger 3 that exchanges heat and stores heat in the heat storage material 2, and also exchanges heat with a second heat medium to dissipate heat from the heat storage material 2. The heat storage material 2 has erythritol 20 and water 21. The mixing ratio of erythritol 20 to water 21 is 60 [wt%] or more and 80 [wt%] or less by weight. That is, in the heat storage type water heater 100 according to the first embodiment, the temperature (melting point) at which the erythritol 20 undergoes a phase change when the erythritol 20 is dissolved in water 21 is set in the range of 40 ° C. to 90 ° C. for hot water supply. It can be lowered to 60 ° C to 90 ° C, which is suitable for use. As a result, the latent heat of the erythritol 20 can be sufficiently released, and the amount of heat stored in the heat storage material 2 can be improved. Therefore, since the heat storage type water heater 100 can improve the heat storage amount of the heat storage material 2 even when the heat storage material 2 containing erythritol 20 as a main component is used, the heat storage material 2 to be filled in the container 1 can be improved. By reducing the amount of, it is possible to realize miniaturization as a whole.

Further, the heat storage type water heater 100 according to the first embodiment further includes a stirrer 6 for stirring the heat storage material 2. The heat storage type water heater 100 can reduce the solid phase amount of erythritol 20 deposited on the surface of the heat exchanger 3 by stirring the heat storage material 2 with the stirrer 6, so that the heat exchange of the heat exchanger 3 can be performed. It is possible to suppress the deterioration of performance. Therefore, since the heat storage type water heater 100 is provided with the stirrer 6 so that the heat exchange performance can be sufficiently exhibited even if the heat exchanger 3 is miniaturized, the heat exchanger 3 is miniaturized to reduce the size of the entire device. It can be miniaturized.

Further, the heat storage material 2 has a property of being separated into a solid phase portion B in which the erythritol 20 is precipitated and an aqueous solution portion A in which the solid phase of the erythritol 20 is not precipitated at the time of heat dissipation. In the stirrer 6, the stirring blade 60 is arranged at a portion where the aqueous solution portion A is located in a state where the solid phase portion B and the aqueous solution portion A are separated at the time of heat dissipation. Therefore, in the heat storage type water heater 100, since the stirring blade 60 can stir the heat storage material 2 without causing a power decrease due to the solid phase of the erythritol 20, stable heat exchange is possible and the hot water supply performance can be improved.

FIG. 4 is a schematic view showing a modified example of the heat storage type water heater according to the first embodiment. As shown in FIG. 4, the heat storage type water heater 100 may include the heat exchanger 3 as one heat exchanger that both stores heat and dissipates heat from the heat storage material 2. That is, since the heat storage heat exchanger 5 may be configured to store heat in the heat storage material 2 in FIG. 1, hot water supply water can be used as the heat medium flowing through the heat storage heat exchanger 5. Therefore, it is also possible to use the heat dissipation heat exchanger 4 as the heat storage heat exchanger 5 without using the heat storage heat exchanger 5. That is, in FIG. 4, the heat radiating heat exchanger 4 is also used as the heat storage heat exchanger 5, and the heat storage of the heat storage material 2 is performed by flowing high temperature water through the heat radiating heat exchanger 4.

Embodiment 2.
Next, the heat storage type water heater 101 according to the second embodiment will be described with reference to FIG. FIG. 5 is a schematic view showing the internal configuration of the heat storage type water heater according to the second embodiment in a state when the heat storage material dissipates heat. In the second embodiment, the same parts as those in the first embodiment are designated by the same reference numerals, the description thereof will be omitted, and the differences from the first embodiment will be mainly described.

The heat storage type water heater 101 according to the second embodiment is characterized in that it includes a pump 7 for flowing the heat storage material 2 in place of the stirrer 6 of the heat storage type water heater 100 according to the first embodiment. ..

(Structure of heat storage type water heater 101)
First, the configuration of the heat storage type water heater 101 will be described. As shown in FIG. 5, the heat storage type water heater 101 according to the second embodiment has a container 1, a heat storage material 2 filled inside the container 1, and heat exchange for heat dissipation housed inside the container 1. It includes a container 4, a heat storage heat exchanger 5, and a pump 7 for flowing the heat storage material 2 inside the container 1.

In addition to the configuration described in the first embodiment, the container 1 is connected to a suction pipe port 10 to which a pump 7 is connected to discharge the heat storage material 2 to the outside of the container 1, and a pump 7 is connected to the container 1 to discharge heat. A discharge pipe port 11 for allowing the material 2 to flow into the container 1 again is formed.

The pump 7 is a device that sucks and discharges a fluid such as a centrifugal pump, a constant volume pump, or a plunger type pump. The material of the pump 7 is, for example, a strong material such as aluminum or SUS, or a lightweight material such as plastic. In the pump 7, the suction port is connected to the suction pipe port 10 of the container 1, and the discharge port is connected to the discharge pipe port 11 of the container 1.

In the heat storage type water heater 101 according to the second embodiment, the heat source machine that gives heat to the heat storage material 2 on the circuit from the suction pipe port 10 to the pump 7 of the container 1 and the heat radiation radiated from the heat storage material 2 It shows the case of not having a vessel. However, the heat storage type water heater 101 may have other devices arranged on the circuit as long as the pump 7 is used to circulate the heat storage material 2 in the container 1.

(Heat storage operation of heat storage type water heater 101)
Next, the heat storage operation of the heat storage type water heater 101 will be described. Similar to the first embodiment, the heat storage type water heater 101 according to the second embodiment has fins from the heat storage tube 5a when a high temperature heat medium flows from the heat medium inflow pipe 5b of the heat storage heat exchanger 5. Heat is transferred to the heat storage material 2 via. In the heat storage type water heater 101, when the low temperature heat storage material 2 is warmed and the temperature rises to reach the melting point, the solid phase of erythritol 20 melts and becomes a liquid phase. On the other hand, the temperature of the heat medium that gives heat to the heat storage material 2 drops, and the heat medium is discharged from the heat medium outflow pipe 5c. Further, at the time of heat storage, the heat storage material 2 can be flowed by driving the pump 7 to discharge the heat storage material 2 to the outside of the container 1 and allowing the discharged heat storage material 2 to flow into the container 1 again. .. By flowing the heat storage material 2, the heat exchange performance between the heat storage material 2 and the heat medium is improved. Here, the heat source machine for heating the heat medium flowing through the heat storage heat exchanger 5 may be a heat pump, a heater, or a combustor, as long as it can heat the heat medium. Further, even if the system for heating the heat medium is a circulation type system that is discharged from the heat medium outflow pipe 5c, flows through the heat source machine, and flows into the heat storage heat exchanger 5 again from the heat medium inflow pipe 5b, the heat medium outflow pipe. It may be a transient type that is discharged from 5c to the outside and does not circulate.

(Heat dissipation operation of heat storage type water heater 101)
Next, the heat dissipation operation of the heat storage type water heater 101 will be described. In the heat storage type water heater 101 according to the second embodiment, as in the first embodiment, when the hot water supply water flows from the hot water supply water inflow pipe 4b of the heat dissipation heat exchanger 4, the heat of the heat storage material 2 causes the fins 4d. The temperature of the hot water supply water that is transmitted to the heat radiating heat transfer tube 4a and flows inside rises. At the same time, the heat storage material 2 is deprived of heat and the temperature drops. Then, the temperature of the heat storage material 2 around the heat radiating heat transfer tube 4a reaches the melting point, and a solid phase of erythritol 20 is deposited around the heat radiating heat transfer tube 4a. The hot water supply water to which heat is applied from the heat storage material 2 and the temperature rises is discharged from the hot water supply water outflow pipe 4c. Further, at the time of heat dissipation, the heat storage material 2 can be made to flow by driving the pump 7 to discharge the heat storage material 2 to the outside of the container 1 and allowing the discharged heat storage material 2 to flow into the container 1 again. .. The solid phase of erythritol 20 has a lower thermal conductivity than substances such as metals. Therefore, in the heat storage type water heater 101, the heat exchange performance between the heat storage material 2 and the heat medium can be improved by flowing the heat storage material 2 with the pump 7.

(Arrangement position of suction pipe port 10 and discharge pipe port 11)
Next, the arrangement positions of the suction pipe port 10 and the discharge pipe port 11 of the container 1 will be described. The heat storage material 2 in the heat storage type water heater 101 of the second embodiment is also a mixed solution of erythritol 20 and water 21 as in the first embodiment. The concentration of erythritol 20 in the heat storage material 2 is calculated by the formula (1) using the temperature of the heat storage material 2.
x = -0.00387T ² + 1.34T-5.94 (1)
x is the erythritol concentration [wt%] in the heat storage material 2. T is the temperature [° C.] of the heat storage material 2. That is, the solid phase amount of erythritol 20 precipitated from the heat storage material 2 and the liquid phase amount with the heat storage material 2 are uniquely determined according to the temperature of the heat storage material 2 at the time of heat dissipation. On the other hand, the suction pipe port 10 and the discharge pipe port 11 of the container 1 should be arranged in the aqueous solution portion A of the heat storage material 2. This is because if the suction pipe port 10 and the discharge pipe port 11 are arranged in the solid phase portion B, the solid phase of erythritol 20 is deposited in the pipe, and the solid phase blocks the inside of the pipe. .. Therefore, the heat storage type water heater 101 includes the solid phase portion B and the aqueous solution portion A at the time of heat dissipation based on the above formula (1) and the solid phase amount of erythritol 20 calculated based on the temperature of the heat storage material 2 at the time of heat dissipation. By arranging the suction pipe port 10 and the discharge pipe port 11 in the portion where the aqueous solution portion A is located in the separated state, stable heat exchange is possible and the hot water supply performance is improved.

As described above, also in the heat storage type water heater 101 according to the second embodiment, the temperature (melting point) at which the erythritol 20 undergoes a phase change when the erythritol 20 is dissolved in water 21 is set to 40 ° C. to 90 ° C. for hot water supply. The temperature can be lowered to 60 ° C. to 90 ° C., which is suitable for use in the range of. As a result, the latent heat of the erythritol 20 can be sufficiently released, and the amount of heat stored in the heat storage material 2 can be improved. Therefore, since the heat storage type water heater 101 can improve the heat storage amount of the heat storage material 2 even when the heat storage material 2 containing erythritol 20 as a main component is used, the heat storage material 2 to be filled in the container 1 can be improved. By reducing the amount of, it is possible to realize miniaturization as a whole.

Further, the heat storage type water heater 101 according to the second embodiment causes the heat storage material 2 to flow by discharging the heat storage material 2 to the outside of the container 1 and allowing the discharged heat storage material 2 to flow into the inside of the container 1 again. A pump 7 for making the pump 7 is further provided. A suction pipe port 10 to which a pump 7 is connected to discharge the heat storage material 2 to the outside of the container 1 and a discharge pipe port 10 to which the pump 7 is connected to discharge the discharged heat storage material 2 into the inside of the container 1 again are connected to the container 1. The piping port 11 is formed. Therefore, in the heat storage type water heater 101, the solid phase amount of erythritol 20 deposited on the surface of the heat exchanger 3 can be reduced by driving the pump 7 to flow the heat storage material 2. It is possible to suppress the deterioration of the heat exchange performance of 3. Therefore, since the heat storage type water heater 101 is provided with the pump 7, the heat exchange performance can be sufficiently exhibited even if the heat exchanger 3 is miniaturized. Therefore, the heat exchanger 3 is miniaturized and the device as a whole is miniaturized. Can be transformed into.

The heat storage material 2 has a property of being separated into a solid phase portion B in which the erythritol 20 is precipitated and an aqueous solution portion A in which the solid phase of the erythritol 20 is not precipitated at the time of heat dissipation. In the container 1, a suction pipe port 10 and a discharge pipe port 11 are formed at a portion where the aqueous solution part A is located in a state where the solid phase part B and the aqueous solution part A are separated at the time of heat dissipation. Therefore, the heat storage type water heater 101 can prevent a situation in which the inside of the pipe is blocked by the solid phase of erythritol 20 deposited in the pipes of the suction pipe port 10 and the discharge pipe port 11, so that the heat storage type water heater 101 can store heat. The material 2 can be made to flow to enable stable heat exchange, and the hot water supply performance can be improved.

In the heat storage type water heater 101 according to the second embodiment, the heat exchanger 3 may be composed of one heat exchanger that both stores heat and dissipates heat from the heat storage material 2. That is, since the hot water supply water can be used as the heat medium flowing through the heat storage heat exchanger 5, the heat heat exchanger 4 for heat dissipation should be used as the heat storage heat exchanger 5 without using the heat storage heat exchanger 5. Is also possible.

Although the heat storage type water heaters 100 and 101 have been described above based on the embodiment, the heat storage type water heaters 100 and 101 are not limited to the configuration of the above-described embodiment. For example, the heat storage type water heaters 100 and 101 are not limited to the above-mentioned components, and may include other components. In short, the heat storage type water heaters 100 and 101 include a range of design changes and application variations normally performed by those skilled in the art within a range that does not deviate from the technical idea thereof.

1 container, 2 heat storage material, 3 heat exchanger, 4 heat heat exchanger for heat dissipation, 4a heat transfer pipe for heat dissipation, 4b hot water supply water inflow pipe, 4c hot water supply water outflow pipe, 4d fin, 5 heat storage heat exchanger, 5a heat storage Heat transfer pipe, 5b heat medium inflow pipe, 5c heat medium outflow pipe, 6 stirrer, 7 pump, 10 suction pipe port, 11 discharge pipe port, 20 erythritol, 21 water, 60 stir blade, 61 rotary machine, 100, 101 Heat storage type water heater, A aqueous solution part, B solid phase part.

Claims (7)

A container that exchanges heat inside and
The heat storage material filled inside the container and
A heat exchanger housed inside the container, which exchanges heat with the first heat medium to store heat in the heat storage material, and exchanges heat with the second heat medium to dissipate heat from the heat storage material.
A device for flowing the heat storage material is provided.
The heat storage material has erythritol and water that dissolves the erythritol.
The mixing ratio of the erythritol to the water is 60 [wt%] or more and 80 [wt%] or less by weight.
At the time of heat dissipation, the heat storage material is separated into a solid phase portion in which the erythritol is precipitated and an aqueous solution portion in which the solid phase of the erythritol is not precipitated, and the heat storage material is flowed by an apparatus for flowing the heat storage material. A heat storage type water heater having a structure in which the solid phase portion is deposited on the lower part of the container and the aqueous solution portion is located on the solid phase portion . Stirrer Bei Eteiru for agitating the heat storage material as a device for flowing the heat storage material, thermal storage water heater according to claim 1. The heat storage type water heater according to claim 2, wherein the stirrer has a stirring blade arranged at a portion where the aqueous solution portion is located in a state where the solid phase portion and the aqueous solution portion are separated at the time of heat dissipation. Examples apparatus for flowing a heat storage material, the heat storage material is discharged to the outside of the container, by flowing into the interior again the container discharge the said heat storage material, Bei Eteori a pump for flowing the heat storage material,
A suction pipe port to which the pump is connected to discharge the heat storage material to the outside of the container and a discharge pipe to which the pump is connected to discharge the discharged heat storage material into the container again. The heat storage type water heater according to claim 1, wherein a pipe port and a pipe port are formed. The container is claimed to have a suction pipe port and a discharge pipe port formed in a portion where the aqueous solution portion is located in a state where the solid phase portion and the aqueous solution portion are separated at the time of heat dissipation. The heat storage type water heater according to 4. The heat exchanger is
A heat exchanger for heat storage through which a heat medium flows,
The heat storage type water heater according to any one of claims 1 to 5, further comprising a heat exchanger for heat dissipation through which hot water is flowing. The heat storage type water heater according to any one of claims 1 to 6, wherein the heat exchanger is composed of one heat exchanger that has both heat storage and heat dissipation of the heat storage material.

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