JP2006002976A - Heat storage body, heat storing method, space heater and water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat storage body of small capacity, capable of efficiently storing heat. <P>SOLUTION: This heat storage body 1 has a heat storage material and a heat transfer material for transferring the heat to the heat storage material. The heat storage material and the heat transfer material are stored, for example, inside of a container 2. The heat transfer material is composed of foam metal 3 having a number of pores, and the foam metal 3 is mounted in a state of being kept into contact with the heat storage material. By placing the heat storage material in the pores of the foam metal, the heat can be efficiently moved between the inside and the outside of the heat storage material of small heat conductivity. The effect can be improved by using pentaerythritol as the heat storage material. Further by using nickel-chrome alloy foam metal 3 of high electric resistance, the heat storage body can be effectively used as a heat generating material. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat storage body, a heat storage method, a heater, and a water heater. In particular, the present invention relates to a heat storage body suitable for use in a heater or a water heater for heating or hot water supply using energy stored at night using midnight power or the like.

  With the increase in power demand, the difference in power load between day and night is increasingly widening. As a measure for leveling the electric power load, many heat storage devices are installed in building heating, cooling, water heaters, and the like.

  As a heat storage body used for such a heat storage apparatus, there is a heat storage body in which paraffin which is a heat storage material is placed in a steel tank. However, since solid paraffin has poor thermal conductivity, it is necessary to store carbon fiber in a container as a heat transfer accelerator. Since the carbon fiber is expensive, this technique has difficulty in practical use.

  There is also a static heat storage device that uses solid ice as a heat storage material (for example, Patent Document 1). In this apparatus, a water-absorbing material composed of water-absorbing fibers and the like is swollen with water to form a water-containing heat storage body, and the water-containing heat storage body is filled in a heat storage tank together with a refrigerant that is not compatible with water. This is an ice heat storage device that freezes and thaws the water-containing heat storage body by flowing a refrigerant between the water-containing heat storage body. When water is cooled and ice is generated on the heat transfer surface, the heat conductivity of the ice is low, so the ice itself becomes a thermal resistor, and the heat transfer characteristics deteriorate with the progress of operation. The operating efficiency of the system is reduced.

  In addition, there is also a heat storage device using two liquids having different freezing points (for example, Patent Document 2). That is, two liquids having different freezing points are used to cool the liquid with the liquid. In the heat storage tank containing a large amount of the first liquid, which is a heat storage body, the low-temperature second liquid is blown into the first liquid to make it ice and solidify. Patent Document 2 provides a latent heat storage device that can control the ice making and the flow of the second liquid inside the heat storage tank in this ice making process, and can improve the ice filling efficiency and the ice-melting effect.

JP-A-6-249474 Japanese Patent Laid-Open No. 7-19536

  However, the technique described in Patent Document 2 has a problem that the heat storage device becomes large. That is, this heat storage device uses two types of liquids. Therefore, in addition to the heat accumulator, a second liquid, piping for heat transfer, a device for heating and cooling the second liquid, a pump, etc. are required, and the device configuration other than the heat accumulator is increased, The heat storage device must be large.

  Accordingly, a main object of the present invention is to provide a heat storage body that is compact and can store and release heat efficiently.

  This invention achieves said objective by using a foam metal for a heat-transfer material in the heat storage body which has a heat-transfer material and a heat storage material.

  The heat storage body of the present invention has a heat storage material and a heat transfer material that transfers heat to the heat storage material, and the heat transfer material is made of a foam metal having a large number of holes, and the foam metal is in contact with the heat storage material. It is arranged.

  Since the heat storage material generally has a low thermal conductivity, it is difficult to heat the inside of the heat storage material or to extract the heat stored in the heat storage material to the outside. Therefore, the present invention solves this problem by using a foam metal as a heat transfer material. That is, in the present invention, by using the foam metal as a good heat conductor, efficient heat transfer is performed to the heat storage material, and sufficient heat storage inside the heat storage material is also possible. On the contrary, when taking out the heat inside the heat storage material to the outside, the foam metal becomes a good conductor of heat, and the heat inside the heat storage body can be taken out efficiently.

  It is important that the foam metal is placed in contact with the heat storage material. By bringing the foam metal into contact with the heat storage material, efficient heat conduction can be performed. With this configuration, the contact area between the foam metal and the heat storage material is increased, and more efficient heat conduction is possible. Therefore, by using the foam metal, it is possible to provide a heat storage body capable of storing heat and releasing heat in a compact and efficient manner.

The heat storage material is preferably pentaerythritol. Pentaerythritol (C ₅ H ₁₂ O ₄ ) undergoes a solid phase / solid phase crystal transition at 188 ° C., has a very large heat of transition (latent heat amount is 104 cal / cc), and is crystalline in a heat storage state. It is a material that is easy to handle.

  The foam metal is preferably a nickel-chromium alloy. While using a foam metal as a heat generating material, it is used to transmit the heat inside the heat storage body to the outside. The electrical resistance and thermal conductivity of the nickel-chromium alloy are balanced for the above purpose. The foam metal is a porous metal body having a large number of pores. Typically, the void ratio is 90% by volume or more and 98% by volume or less, and the rest is made of metal. More specifically, Celmet (registered trademark) manufactured by Sumitomo Electric Industries, Ltd. may be mentioned. This cermet is generally manufactured by plating a foamed urethane resin or the like with a metal and then removing the resin by heating.

  Moreover, this invention heat storage method uses said heat storage body, It is characterized by the above-mentioned. That is, using the heat storage body, the heat generated by energizing the foam metal included in the heat storage body is stored in the heat storage body. Since the heat storage material is provided in the pores of the foam metal having a high thermal conductivity, the contact area with the foam metal is increased and heat can be efficiently stored up to the inside of the heat storage material.

  Next, this invention heater uses said heat storage body, It is characterized by the above-mentioned. That is, it is a heater provided with said heat storage body, Comprising: It has an air supply port which supplies gas around the said heat storage body, and an exhaust port which discharges | emits the gas heated with the heat | fever of the heat storage body. Since the gas heated by the heat of the heat storage body can be discharged from the exhaust port as warm air, a clean and efficient heater can be configured.

  The heat storage body may be heated by energizing the foam metal provided in the heat storage body to generate heat. That is, heat is once stored in the heat storage body, and heating is performed using the heat.

  Furthermore, this invention water heater is characterized by using said heat storage body. That is, it is a water heater provided with the said heat storage body, Comprising: It has a water supply port which supplies water around the said heat storage body, and a drain outlet which discharges | emits the warm water heated with the heat | fever of the heat storage body.

  Even in this water heater, the heat storage body may be heated by energizing a foam metal provided in the heat storage body to generate heat. That is, heat is once stored in the heat storage body, and hot water is supplied using the heat.

  In the present invention, the heat storage material can be efficiently heated and cooled by using the foam metal as a heat transfer material and contacting the foam metal and the heat storage material.

  Moreover, when radiating the heat stored in the heat storage material, the heat can be efficiently radiated through the foam metal having high thermal conductivity.

  Since the heat generating material and the heat storage material can be mixed in the same space, the size of the heat storage body can be made compact.

  FIG. 1 is an external perspective view showing an example of a heat storage body of the present invention. The heat storage body 1 has a configuration in which a foam metal 3 is housed in a container 2 as a good heat conductor, and a heat storage material is arranged around the foam metal 3 and in the holes.

  The ends of the foam metal 3 are electrically connected by a connecting wire 4. In this example, a plurality of elongated rod-shaped foam metal 3 are aligned in the row direction and the column direction in the container 2. One end and the other end of the foam metal 3 adjacent to each other in the row direction are alternately connected in series, and the foam metal 3 located at one end of each row and the end of the foam metal 3 in the same row in the next row of the foam metal The parts are connected to each other, and all the foam metal 3 is connected in series. Then, the lead wire 6 is connected to both ends of the foam metal 3 connected in series, and the tip is connected to the power source 7, whereby the foam metal 3 can be heated by energization heating.

  The end of the foam metal 3 protrudes from the spacer 10 and is stored in the lid 5 that covers the container 2. Inside the container 2, since the heat storage material is provided in the pores of the foam metal 3, heat conduction can be improved to the inside of the heat storage material.

  The foam metal 3 used here is a material having a void ratio of 90 volume% or more and 98 volume% or less, and the remainder made of metal. Generally, it is manufactured by removing a resin after plating a foamed urethane resin or the like with a metal. In the foam metal having the same shape, the electrical resistance is increased because the amount of metal is reduced when the proportion of the holes is increased. In this example, Selmet (registered trademark) manufactured by Sumitomo Electric Industries, Ltd. was used.

  FIG. 2 is a front view showing an example in which a foam metal is assembled so that the heat storage body of the present invention can be used, and FIG. 3 is a top view thereof. The dotted lines in FIGS. 2 and 3 indicate the container, and the foam metal is accommodated in the container. These drawings are examples in which a large number of rod-shaped foamed metals 3 are attached to a spacer 10 for assembly.

  One method of using a foam metal as a heat generating material is to connect a thin rod-shaped foam metal 3 in series to match a predetermined electric resistance. At this time, when the metal foams come into contact with each other, they are short-circuited. Therefore, it is preferable to prevent contact with the spacer 10 using an insulating material and to assemble as one block. Here, a frame-shaped spacer 10 in which rectangular holes according to the arrangement of the foam metal 3 are aligned in the row direction and the column direction is used, and the upper and lower portions of the foam metal are held by the spacer 10. . As a result, since a plurality of foamed metals 3 can be handled as an assembly, handling becomes easy.

A heat storage body that can store 1kWh of heat and midnight power in 8 hours was designed and manufactured by the following method. Pentaerythritol was used as the heat storage material. In order to store the amount of heat corresponding to 1 kWh, considering the calorific potential of 104 cal / cc when causing the crystal transition of solid phase / solid phase of pentaerythritol at 188 ° C,
Since 1 kWh = 859,845 cal, the required volume of heat storage material is approximately 8.3 liters according to the following calculation.
859,845cal ÷ 104cal / cc = 8268cc

Next, a heat transfer material made of foam metal was examined. In this case, the heat transfer material is also used as a heat generating material. In order to generate 1 kWh in 8 hours with a power supply voltage of 200 V, 1 kWh ÷ 8 h = 125 W, so the required electrical resistance value is (200 V) ² ÷ 125 W = 320 Ω.

When calculated from the resistivity of a general Ni—Cr alloy as a heating material, the electrical resistance of a 1 mm ² cross-sectional area and a length of 1 m is 1Ω. The shape of the metal foam heating material is 1mm x 10mm x 900mm. Foam metal is a highly porous material in which the metal occupies 5% by volume and the remainder is a void. In this example, 95% by volume of holes were used. Since 100% of the length of the metal foam is used, where 5% by volume is the metal percentage, 5% is the percentage of the cross-sectional area of the metal foam. Therefore, when calculating the cross-sectional area of the foam metal
A ^{1mm × 10mm × 0.05 = 0.5mm 2} .
If the length of 900 mm is taken into consideration, the electrical resistance of this shape of the heating material is 1.8Ω.

  First, an iron container of 950 mm × 100 mm × 100 mm was produced. The foam metal designed as described above was manufactured and confirmed to have the electrical resistance as designed. 178 of these were collected and assembled using spacers made of insulating resin as shown in FIGS. All the foam metals were connected by connecting wires so that they were in series.

  This is inserted into the iron container and filled with 8.3 liters of pentaerythritol as a heat storage material. First, the container and the metal foam were heated to 250 ° C., and liquid pentaerythritol heated to about 250 ° C. was poured into the container in a vacuum.

  By doing in this way, the metal foam was buried in the heat accumulator, and the heat accumulator was provided in the pores of the metal foam. After assembling the heat storage body as shown in FIG. 1, the lead wires were connected to a 200 V power source to heat the heat storage material. It was confirmed that it had the heat storage capacity as designed.

  Using the heat storage body created in Example 1, a heater and a water heater were produced. FIG. 4 is an example in which a plurality of heat accumulators 1 are assembled and used in the heater 20. The air is taken in from the outside by a fan 21 serving as an air supply port, passes through the periphery of the heat storage body 1 as indicated by an arrow, and then exits from the exhaust port 22. At this time, since the air is warmed by the heat accumulator and discharged as warm air, the warm air can be used for heating.

  On the other hand, a water heater can be obtained as follows. That is, in FIG. 5, water is introduced from the water supply port 23 and is sent in the direction of the arrow. Since water passes around the heat storage body 1, the water is warmed by the heat storage body 1 and goes out from the drain outlet 22 as warm water. By using this warm water, it becomes a water heater.

  Since the heat storage body obtained by the present invention is compact, it is used in fields such as a heater and a water heater.

The perspective view of the thermal storage body of this invention. The front view which shows the state which fixed the rod-shaped metal foam used for this invention heat storage body to the spacer. The top view which shows the state which fixed the rod-shaped foam metal used for this invention heat storage body to the spacer. The schematic block diagram of the heater using the heat storage body of this invention. The schematic block diagram of the water heater using the thermal storage body of this invention.

Explanation of symbols

1 Thermal storage 2 Container
3 Foam metal 4 Connecting wire
5 Lid 6 Lead wire
7 Power supply
10 Spacer
20 Heater 21 Fan
22 Exhaust (water) port 23 Water supply port

Claims (9)

It has a heat storage material and a heat transfer material that transfers heat to the heat storage material,
The heat transfer material is made of a foam metal having a large number of pores,
The heat storage body, wherein the foam metal is disposed in contact with the heat storage material.   2. The heat storage body according to claim 1, wherein the heat storage material is provided at least in the pores of the foam metal.   The heat storage material according to claim 1, wherein the heat storage material is pentaerythritol.   4. The heat storage body according to claim 1, wherein the foam metal is made of a nickel-chromium alloy. Using the heat storage element described in any one of claims 1 to 4,
A heat storage method characterized in that heat generated by energizing a foam metal included in the heat storage body is stored in the heat storage body. A heater provided with the heat storage body according to any one of claims 1 to 4,
An air supply port for supplying a gas around the heat storage body;
A heater having an exhaust port for discharging a gas heated by heat of the heat storage body.   7. The heater according to claim 6, wherein heat generated by energizing the foam metal is stored in a heat storage body. A water heater comprising the heat storage element according to any one of claims 1 to 4,
A water supply port for supplying water around the heat storage body;
A water heater having a drain outlet for discharging hot water heated by heat of a heat storage body.   9. The water heater according to claim 8, wherein heat generated by energizing the foam metal is stored in a heat storage body.

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