JPS61261388A - Heat storing apparatus - Google Patents

Abstract

PURPOSE:To efficiently utilize heat, by transferring heat to a heat-storing medium via heat conduction means to convert the crystalline phase of the heat- storing medium into the gel phase for storing heat and stimulating the gel phase to convert it into the crystalline phase at the time of use for generating heat. CONSTITUTION:The titled apparatus will be described with reference to an immediately actuating heater of a heat-storing type which uses engine cooling water. A warmed cooling water C used for cooling an engine 3 is fed to a hot water pipe 14 of a heat-storing apparatus 1 to rapidly transfer the heat to a heat-storing medium 18 (e.g.: sodium acetate monohydrate), which is in a crystalline state, through foamed metal 17 and ceramic powder 18a to allow the heat-storing medium to gel, thereby storing latent heat in a supercooled state. At the time of use, a stimulating device 19 of the heat-sotring apparatus 1 is actuated so as to bring fine crystal nuclei into contact with the heat-storing medium 18 in the state of gel to quickly crystalline the medium, thereby releasing the heat. Thus, the air fed to the heat-storing apparatus is warmed and blown out by means of a fan, enabling the driver to warm his hand.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a heat storage device that utilizes latent heat accompanying the melting and solidification of salt hydrate, and is effective when used in instant-acting heaters for automobiles and other instant heating devices. be.

(Prior art) In general, as heat storage materials, there are sensible heat storage media that utilize only the temperature rise of a substance that serves as a heat medium, and latent heat heat storage that utilizes heat absorption and radiation caused by phase changes such as melting and solidification of substances that serve as a heat medium. medium is known. Among these, the latter latent heat storage medium has the advantage that it can be expected to store a large amount of heat in a narrow temperature range and can obtain heat at a constant temperature. A wide variety of materials such as paraffin, clathrate hydrates, salt hydrates, molten salts, and metals have been studied as such media.

Among these media, as shown in Japanese Unexamined Patent Publication No. 59-53578, a hydrophilic polysaccharide is mixed in sodium acetate hydrate, and a supercooled gel state of IJium trihydrate is prepared by mixing a hydrophilic polysaccharide with acetic acid. It is known to store heat by stably storing it, and release heat when necessary by releasing the supercooled gel state.

(Problems to be Solved by the Invention) However, in the above heat storage system, it is necessary to completely convert the sodium acetate trihydrate, which is the heat storage medium, into a gelatinous salt during the heat absorption process, and even a very small amount of sodium acetate trihydrate needs to be converted into a gelatinous salt. If some solid hydrated salt remains, the endothermic process is stopped and as the temperature decreases, the remaining small amount of solid hydrated salt becomes a nucleus and the gel-like hydrated salt gradually becomes solid. It undergoes a phase transition to a hydrated salt and releases latent heat accordingly. Therefore, there was a problem that heat could not be extracted when necessary.

If you want to use the above heat storage system, for example, as an instant heater for automobiles, rapid heating of fuel, rapid heating of battery fluid, etc., use engine cooling water (82 to 95 degrees Celsius when the engine is running) or exhaust heat as the heat source. However, when engine cooling water is used as a heat source, a relatively low-temperature heat source is used during the heat absorption process of the heat storage medium, and sodium acetate trihydrate can be completely converted into a gel in a short time with thermal efficiency. must be done. Furthermore, although the exhaust heat is high temperature, the exhaust pipe is located in a location that is difficult to access, so an appropriate heat transfer means is required. As described above, in this type of heat storage device, an appropriate heat conduction means is essential in order to promptly cause the phase transition of the heat storage medium from the crystalline phase to the gel phase.

In view of the above points, the present invention aims to conduct heat from a heat source to a heat storage medium relatively quickly in a heat storage system using sodium acetate hydrate or the like.

(Means for Solving the Problems) The means of the present invention for achieving the above object is to provide a heat conduction promoting means for promoting the phase transition from the crystal phase to the gel phase of the heat storage medium.

(Function) According to the above means, the heat supplied from the heat source is quickly and efficiently transmitted into the heat storage medium by the heat conduction promoting means, and is completely transferred to the gel phase, which is the heat storage phase, which is highly hydrated. The endothermic process can be completed in a short time.

(Effects of the Invention) Therefore, the present invention has an excellent effect in that it can be used, for example, in a heat storage system for an automobile, and can store heat in a short period of operation.

(Example) The present invention will be described below based on an example shown in the drawings. 1st
The figure is a diagram illustrating the configuration of a regenerative type instant-acting heater using engine cooling water according to the present invention.

1 is a heat storage/heat storage device of the present invention, 2 is a water jacket of an engine 3, 4 is a radiator for cooling engine cooling water, and 5 is a fan for forcing air into the radiator 4.

The engine water jacket 2 and the radiator 4 are connected through a radiator pipe A so that cooling water can be circulated therethrough, and water is supplied by a water pump 6. Furthermore, 4a
is a thermostat that switches on/off the water supply to the radiator 4. Piping B connects the engine cooling water to the air conditioning heater core 7.
A water pump 6 circulates water through a heating pipe that performs heating by passing water through the heating pipe.

Piping C is a heat storage device pipe that branches from the outgoing route of heating pipe B and joins the return route of pipe B via heat storage device 1 . Note that the water pump 6 is always driven, so
Bypass piping is provided for when water supply to the radiator 4, heater core 7, and heat storage device 1 is all stopped.

Next, the structure of the heat storage device 1 will be explained in detail. 1° is a cylindrical container with a double structure made of metal such as iron, aluminum, or brass, and a heat insulating material 11 such as ceramic fiber or asbestos is filled between the outer container 10a and the inner container 10b to prevent heat from going to the outside. The structure is such that the radiation is small. Further, the inner surface of the inner container 10b is painted, galvanized, etc. to provide corrosion resistance. Reference numeral 12 denotes a pipe that passes through the container 10 in the axial direction, and is made of the same material as the container 10, and is airtightly connected to the container 10 by penetrating portions 12a, 12b, welding, brazing, etc. A large number of pleated fins 13 are provided on the inner surface of the pipe 12 to promote heat exchange.

Reference numeral 14 denotes a hot water pipe for passing engine cooling water, which is spirally arranged in the container 10 so as to surround the pipe 12, and is made of the same material as the container 10 and the pipe 12;
The entrance and exit part with 0 is connected by welding, brazing, etc. to prevent leakage. Note that the outer peripheral surfaces of the pipes 12 and 14 are as follows:
Similar to the inner surface of the container 10, anti-corrosion treatment is applied. Both ends of this hot water pipe 14 are connected to the heat storage device pipe C.
Solenoid valves 15 and 16 are provided on the upstream and downstream sides of the heat storage device 1.

In the space surrounded by the inner container 10b of the container 10 and the outer peripheral surface of the pipe 12.14, a foamed metal 17 (pore density 8 mesh/inch, porosity 9
0 to 97%) is filled over the front surface, and the foamed metal and the hot water pipe 4 are joined by brazing as shown in Fig. 2, so that the soldering is done so that good heat conduction is achieved on the surface 17a. has been done. The foamed metal 17 has a three-dimensional network shape, as shown in FIG. 3, and is made by electroplating nickel-chromium on the surface of a polyurethane foam. After pouring stainless brazing material on the surface of the hot water pipe 14 at 800 to 1000 degrees, foaming the urethane foam in the container, and then electroplating to form a foamed metal, the urethane foam is burned out at the same time. Manufactured by brazing.

In addition, the air conditioning section 17c formed by the three-dimensional mesh skeleton 17b of the foamed metal 17 is filled with a total amount of about 2.5 kg of heat storage medium 18 made of sodium acetate trihydrate, and the hot water pipe 14 and the foamed metal It receives heat conduction from the metal 17 and is heated into a gel state, which is then cooled to form a supercooled gel state and heat is stored in this state.

Note that the heat storage medium 18 is press-fitted into the foamed metal 17 while being vibrated in a gel state.

The heat storage principle of sodium acetate is explained below. Sodium acetate trihydrate (CH3C00Na-nH20,
n = 2.5 to 3.5) absorbs heat and becomes gel-like when the temperature reaches 65°C, and if it becomes completely gel-like, it will not crystallize even if the temperature drops (even below 65°C). (transition to a less hydrated phase) and remains in a gel state (more hydrated phase) (supercooled state). When you want to release heat, by applying mechanical stimulation etc., the supercooled state suddenly collapses and changes from a gel state to a crystal state, and at this time 40
Releases ~60 cal/g of heat. At this time, if the gel state is not completely formed and some crystalline state remains, the remaining crystals serve as nuclei and the temperature decreases (as the gel state gradually crystallizes spontaneously), Cooling cannot be maintained and long-term heat storage becomes impossible.

At this time, in order to maintain the gel state, it is necessary to control the amount of crystallization water, but it is also necessary to add small amounts of other additives, such as xanthan gum, as disclosed in JP-A-59-53578. 0.0% hydrophilic polysaccharide.
When 0.03 to 0.1% by weight is added, the classic phase transition between the crystalline state and the gel state of the heat storage medium can be caused more stably.

In addition, in order to stably perform reversible phase transition, the amount of crystal water should be
Hs COONa 2.5 to 3, 5 to 1 mo1
In order to ensure that the water content is maintained at mol, sufficient care must be taken to prevent this water content from scattering, and therefore it is necessary to increase the airtightness of the container in which the heat storage medium is stored.

The heat storage medium 18 of the present invention further includes ceramic powder 18a (Si
C powder) is dispersed therein, and the mixing ratio thereof is 10% by weight.

Reference numeral 19 denotes a stimulation device which is a phase transition inducing means for crystallizing the supercooled gel by applying mechanical stimulation to the supercooled gel, and its detailed structure is explained in FIG.

A pipe section 20 that is connected to the outer surface of the container 10 and communicates with the inside of the container 10, and a main body 22 that is threadedly connected to the pipe section 20 through an O-ring 21 are provided with microcrystalline nuclei 23 of sodium acetate trihydrate at the tip. An actuating rod 24 is held so as to be movable up and down, and this actuating rod 24 is provided with a soft magnetic material part 25 integrally provided at the upper part, and a soft magnetic material part 25 provided on the outer periphery of this actuating rod is When the coil 26 is energized, the actuating rod 24 moves downward and the microcrystalline nuclei 23 come into contact with the heat storage medium 18 in a gel state, thereby breaking the supercooled state.

Note that this stimulation device can also be achieved by a device that uses a sharp object (sharp point) such as a metal, or a device that flows a minute current.

Reference numeral 27 denotes a sensor for detecting the complete gel state of the heat storage material provided on the outer periphery of the container 10, the structure of which is shown in FIG. Two electrodes 30a and 30b made of platinum or nichrome are inserted into the heat storage medium 18 through an insulating material 29 made of ceramic resin or the like in a pipe 28 penetrating the heat insulating container 10, and the gap between these two electrodes is The gel state can be detected by utilizing the fact that electrical resistance is different between the gel state and the crystal state.

Further, the sensor 27 is attached to the outer surface of the container 1° near the downstream end of the hot water pipe where the temperature of the hot water flowing through the hot water pipe is lowest.

Further, 31 receives a signal from the engine cooling water temperature detection sensor 32, and opens the solenoid valves 15 and 16 at the same time when the water temperature reaches 65° C. or higher, and the gel state detection sensor 27 causes the heat storage material to be completely in a gel state. This is a control circuit that sometimes controls valves 15 and 16 to close at the same time.

FIG. 6 is a sectional view illustrating a state in which the instant-acting heater of the above embodiment is installed in the driver's seat of an automobile. When the fan 33 installed upstream of the heat storage device 1 operates, outside air is taken in from the outside air intake 34 that opens near the air intake installed on the top of the car hood near the windshield, and the air is taken in from the driver's seat steering wheel. The warm air is opened in the instrument panel of the driver and is configured to be able to be blown out from an air outlet 35 that is provided to blow hot air toward the driver's hands.

Further, a butterfly type damper 37 is disposed on the downstream side of the heat storage device 1 of the pipe 12 so as to open and close the ventilation passage within the pipe 12. In this heat storage device, when the fan 33 is activated by a switch in the center of the steering wheel 36 (not shown), the actuating rod 24 of the stimulating device 19 is activated and comes into contact with the heat storage medium 18 to radiate heat.

Next, the operation in the above configuration will be explained. After the engine is started, the water temperature sensor 32 detects that the temperature of the engine cooling water has reached 65°C or higher, and the control circuit 31 receives this signal and opens the valves 15 and 16, allowing the engine cooling water to pass through the pipe C. hot water pipe 14 in the heat storage container
water is passed through.

and foam metal 17. Heat is quickly transferred by the ceramic powder 18a, and the crystalline heat storage medium 18 gradually begins to gel, and eventually becomes completely gelled.

When the gel state detection sensor 27 detects that the most downstream side of the hot water pipe 14, that is, the lowest temperature part, is completely in a gel state, the control circuit 31 receives this signal and closes the solenoid valves 15 and 16. . In this state, the heat storage material, sodium acetate trihydrate, is completely gel-like, so even if the engine stops and the temperature drops, it can remain supercooled for a very long time and store latent heat.

Next, when the driver's hands are cold, such as when starting to drive a car in cold weather, by turning on the instant-acting heater switch in the center of the steering wheel 36, the heat storage device stimulator 19 is activated.
The coil 26 is energized, the actuating rod 24 is activated, and the microcrystalline nuclei 23 come into contact with the gel-like heat storage medium, so that the gel-like heat storage medium is crystallized at once, with a total crystallization of 1×10 3 to 1.5
Releases x10'kcal of heat. Switch on again
At the same time, the fan 33 is activated to warm the air taken in from the outside air inlet 34 and blow it out from the air outlet 35 to warm the driver's hands. FIG. 7 is a characteristic diagram illustrating the results of measuring the temperature at the outlet of the air outlet 35 after the start of heat radiation, that is, after the switch is turned on. At this time, the outside temperature is 0°C,
The temperature inside the vehicle is 0 to 2°C. As can be seen from the figure, the instant heater of the present invention can blow hot air at 50 to 55° C. toward the driver's hands for about 5 minutes.

Moreover, FIG. 8 compares the time required for complete gelation of the heat storage medium 18 between the heat storage device 1 of the present invention and one that does not use the heat conduction promoting means (foamed metal 17 and ceramic powder 18a) of the present invention. FIG. In the present invention, the heat storage medium 1
Since the foamed metal 17 is spread over the entire surface of the foamed metal 8 and the ceramic powder 18a having good thermal conductivity is dispersed in a high density, complete gelation can be achieved much more quickly. As can be seen from the figure, the heat storage device 1 of the present invention requires only about 17 minutes, which is about 115 minutes compared to a device that does not use heat conduction promoting means.

The heat storage device 1 of the present invention uses the foamed metal 17 and the ceramic powder 18a as heat conduction promoting means, but either one of these may be used as necessary.

Also, instead of the foam metal 17, S iC, A It z
A three-dimensional mesh foam ceramic sintered with O3*TsN-, BeO may also be used.

Figure 9 shows A l z Ox , A 12 N s S
Complete gelation of the heat storage medium 18 when only one of the four types of ceramic powder 18a of t C% B e O is used and the amount added to the heat storage medium per day is varied from 1 wt % to 30 wt % FIG. 3 is a characteristic diagram illustrating the results of measuring the time required to complete the process. As is clear from the figure, the effect of adding ceramic powder is significant at 5 wt% or more.

Moreover, FIG. 10 shows the case where only foamed metal is used, and Ni-
Cr foam metal 17, A j! z Os , S t C
Required time for complete gelation of heat storage medium 18 when four types of foamed ceramics of %T t N % B e O are used and the roughness of the cavity is varied between 5 and 60 mesosh/inch It shows the time. As can be seen from the figure, it is found that a mesh roughness of about 5 mesh/inch or more is sufficiently effective. Furthermore, the above figures 9 and 10
In the experiments shown in the figure, the engine coolant temperature was 80.
It is constant at °C.

Further, in the above embodiment, the configuration is such that outside air is taken in to generate warm air, but the configuration may also be such that the air inside the vehicle is sucked in. Furthermore, the damper 37 that opens and closes the air passage formed by the pipe 12 may be omitted. .

Further, the phase transition inducing means of the present invention is such that a pipe communicating with the inside of the heat storage container 10 is newly provided and the other end is sealed, and a pipe opening/closing means such as a ball valve is interposed in the middle of the pipe. There may be. By making the ball valve part of a resin etc. with a large heat insulating effect, the crystalline phase is maintained at the tip of the ball valve even during the gelation process.
When crystallization is desired, this pulp is opened by the control circuit 31 to collapse the supercooled gel phase in the heat storage container 10 and generate heat.

Next, a second application example of the present invention will be explained.

FIG. 11 is a diagram illustrating the configuration of an application example in which the heat storage device of the present invention is applied to rapid winter heating of battery fluid. In the figure, reference numeral 40 denotes a double-walled heat insulating container having the same material and structure as the first embodiment, and a battery 41 is housed inside. Glued airtight. Further, a hot water pipe 14 is arranged in a spiral manner around the battery 41 in the heat insulating container along the outer peripheral surface. The end portion thereof is airtightly led to the outside of the container 10, and is connected to the hot water pipe C to supply hot water as in the first embodiment. Note that the other configurations are the same as the first
This is similar to the embodiment.

In the above configuration, after heat storage is performed by the same operation as in the first embodiment, for example, when the outside temperature is -40°C, the heat storage medium 18 is 1.5 kg, and the battery capacity is 2I.
1, the battery liquid temperature could be raised to 20-25°C. (In the case of 1 kg, the temperature was 10 to 15 degrees Celsius) In this case, the heat storage system switch was turned off.
NL, Automotive starting switch accessory switch (
When it is in the ACC) position, the operating rod 24 of the stimulation device 19, which is configured to cause heat dissipation of the heat storage device 1, operates, and the microcrystalline nuclei 23 come into contact with the heat storage medium 18 in the supercooled gel state.
To avoid this, the driver must turn the start switch to the ACC position
By stopping the engine for a minute and then setting it to the engine start (starter start) position, the engine can be started quickly and smoothly.

Next, a third application example of the present invention will be explained based on FIG. 12. In the figure, 50 is the fuel carburetor and intake manifold 5
1 pressure (due to pressure fluctuations in the diaphragm chamber 52, the fuel in the float chamber 53 is transferred to the venturi section 5 of the intake pipe 54).
5 is supplied from the fuel discharge port 56 on the upstream side. 5
7 is a throttle valve that adjusts the amount of intake air.

Reference numeral 58 denotes a double-walled heat insulating container having the same material and structure as the first embodiment, and is airtight so as to heat the fuel evaporation section immediately after the venturi section of the intake pipe and the bottom of the float chamber of the fuel vaporizer. installed.

In general, gasoline has a low vapor pressure and is difficult to vaporize at -40°C, so the fuel supplied to the engine combustion chamber is supplied to the intake pipe 5.
4 and the inner peripheral wall surface of the intake manifold 51 in a liquid state, and cannot be supplied in a stable amount to the combustion chamber. The engine can be started very smoothly by heating the fuel in the same manner as in the operating method. Especially in this case, there is no engine jerking phenomenon due to the use of vaporized fuel, and a stable combustion state is obtained.
The amount of unburned hydrocarbons discharged from the combustion chamber is significantly reduced, and lean mixture combustion becomes possible.

Further, the present invention can also be configured to use a heat pipe that utilizes exhaust heat as a heat source and conducts heat from the exhaust pipe into the heat storage device. The exhaust gas temperature is high, and when this temperature is utilized, it is possible to transform the heat storage medium from the crystalline phase to the gel phase in a short time without using the foamed metal or ceramic powder described above.

[Brief explanation of drawings]

FIG. 1 is a system diagram illustrating the configuration of an instant heating system using a heat storage device according to a first embodiment of the present invention, and FIG. 2 shows a hot water pipe 14 of the heat storage device of the present invention in FIG. 3 is an enlarged schematic diagram illustrating the three-dimensional network skeleton structure of the foamed metal used in the heat storage device of the present invention, and FIG. 4 is a cross-sectional view illustrating the structure of the metal joint. FIG. 5 is a cross-sectional view explaining the structure of the stimulation device used, FIG. 5 is a cross-sectional view explaining the structure of the gel state detection sensor used in the heat storage device of the present invention, and FIG. 6 is the vehicle of the heat storage device in the instant heating system of FIG. Schematic diagram explaining the installed state, No. 7
The figure is a characteristic diagram illustrating the heating effect of the instant heating system of the present invention, and Figure 8 shows the time required for complete gelation of the heat storage material between the heat storage device of the present invention and the heat storage device lacking heat conduction promoting means. FIG. 9 is a characteristic diagram comparing the time required for complete gelation of the heat storage material when only various ceramic powders are used as the heat conduction promoting means of the present invention.
Fig. 10 is a characteristic diagram comparing the time required for complete gelation of a heat storage substance when a three-dimensional network structure made of various materials is used as a heat conduction promoting means of the present invention, and Fig. 11 is a characteristic diagram comparing the time required for complete gelation of a heat storage substance. FIG. 12 is a sectional view illustrating the configuration of the second application example, and FIG. 12 is a sectional view illustrating the configuration of the third application example of the present invention. 10...Insulated container, 14...Hot water pipe, 17...
- Foamed metal, 18... Heat storage medium, 18a... Ceramic powder, 19... Stimulator. Representative Patent Attorney Takashi Okabe Fig. 2 Fig. 3 Fig. 4 Fig. 6 Fig. 7

Claims (6)

[Claims] (1) A heat storage medium made of a salt that undergoes a reversible phase transition between a gel phase with high hydration and a crystalline phase with low hydration with the generation and absorption of latent heat, and a supercooled state of the heat storage medium. a phase transition inducing means for stimulating a certain gel phase to transform the supercooled gel phase to a crystalline phase; a heat conduction promoting means for promoting the phase transition from the crystal phase to the gel phase of the heat storage medium; and the heat conduction means. A heat storage device comprising: a heat source that causes the heat storage medium to undergo a phase transition from a crystalline phase to a gel phase by supplying heat to the heat storage medium through the heat storage medium. (2) The heat conduction promoting means is a foamed metal or foamed ceramic having a three-dimensional network structure, and the cavity formed by the three-dimensional network structure is filled with the heat storage medium. A heat storage device according to claim 1. (3) The heat storage device according to claim 1, wherein the heat conduction promoting means is a ceramic powder with high thermal conductivity dispersed in the heat storage medium. (4) The heat conduction promoting means has a ceramic powder with high thermal conductivity dispersed in the heat storage medium and a three-dimensional network structure, and the heat storage is carried out in the cavity formed by the three-dimensional network structure. Claim 1, characterized in that it is made of foamed metal or foamed ceramic filled with a medium.
Thermal storage device described in section. (5) The heat storage device according to claim 1, wherein the heat storage medium is made of a hydrogel made of sodium acetate trihydrate and a hydrophilic polysaccharide. (6) The heat storage device according to claim 1, wherein the ceramic powder is a powder made of at least one selected from silicon carbide, silicon nitride, aluminum nitride, alumina, and beryllium oxide.