JPS6365868B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a solar water heater.

As a solar water heater, a so-called natural circulation type water heater as shown in FIG. 1 is conventionally known. In this water heater, since the hot water storage tank 11 is located above the heat collecting plate 12, there is a problem that the weight of the hot water storage tank is added locally at the installation location, or the heat collecting plate 12 is lifted up by wind. Furthermore, there is also the problem that the amount of heat collected is smaller than that of the forced circulation type described later. On the other hand, although forced circulation water heaters collect a large amount of heat, they have problems in that they are complicated and require installation space to provide a hot water storage tank on the ground, so they have not been widely used in the past.

The present invention has been made in view of the above, and includes:
By configuring the hot water storage tank in a flat plate shape, the purpose is to provide a solar water heater that does not add any local weight.In particular, the purpose is to convert thermal energy into mechanical energy and use this to drive a pump for circulating the heat medium. An object of the present invention is to provide a solar water heater which can be used as a source to reliably circulate a heating medium, and thus can efficiently collect solar heat while having a simple structure.

In the solar water heater of the present invention, a heat collection plate, a heat insulating material, and a flat hot water storage tank are stacked in this order from above, and the outlet of the heat collection plate and the upper part of the hot water storage tank are connected so that water can circulate. In a solar water heater in which the hot plate inlet and the lower part of the hot water storage tank are connected via a pump,
The drive means of the pump generates gas when heated and reversibly absorbs the gas when cooled, and therefore the gas carrier generates gas at higher pressure at higher temperature. A first closed reaction vessel filled with the above-mentioned closed reaction vessel, a second closed reaction vessel filled with the same or different gas carrier or inert gas as above, each communicating with one of these reaction vessels, first and second airtight variable volume containers whose volumes change according to the internal pressure of the gas; and a rigid body coupled between these variable volume containers to convert the change in volume of the variable volume containers into reciprocating motion. When the first reaction vessel is heated, gas is generated from the gas carrier in the vessel, and the internal pressure of the first variable volume vessel communicating with the reaction vessel increases to a second level. When the connecting rod moves in one direction by becoming higher than the internal pressure of the second variable volume container communicating with the reaction container, and then the first reaction container is cooled, the first reaction container is cooled.
When the internal pressure of the variable volume container becomes lower than the internal pressure of the second variable volume container that communicates with the second reaction container, the connecting rod moves in the opposite direction, and in this way, the connecting rod moves back and forth. It is characterized in that the motion is transmitted to the pump via an appropriate transmission mechanism to drive the pump.

The present invention will be described below based on drawings showing examples.

FIG. 2 shows an embodiment of the solar water heater of the present invention, in which a heat collecting plate 21, a heat insulator 22 and a flat hot water storage tank 23 are stacked in this order from above, and a heat collecting plate outlet 24 is stacked so that water can circulate. and the upper part 25 of the hot water storage tank are connected by a connecting pipe 26, and the heat collecting plate inlet 27 and the lower part 28 of the hot water storage tank are connected by a connecting rod 30 equipped with a pump 29.
connected via. Water is supplied to the hot water tank through the water supply pipe 31, cistern 32, and water supply pipe 33, and is forcedly circulated between the hot water tank and the heat collecting plate by the pump.

In the present invention, the pump is driven by a thermal energy to mechanical energy conversion device, as explained below.

The converter is filled with a gas carrier that generates a gas when heated and reversibly absorbs that gas when cooled, thus generating a gas at a higher pressure at a higher temperature. a first sealed reaction vessel filled with the same or different gas carrier or inert gas as above, each communicating with one of these reaction vessels and having a volume thereof first and second airtight variable volume containers whose volume changes in accordance with the internal pressure of the gas; a rigid connection coupled between these variable volume containers to convert a change in volume of the variable volume containers into reciprocating motion; When the first reaction vessel is heated, gas is generated from the gas carrier in the vessel, and the first reaction vessel is connected to the reaction vessel.
When the internal pressure of the variable volume container becomes higher than the internal pressure of the second variable volume container communicating with the second reaction container, the connecting rod moves in one direction, and then the first reaction container is cooled. When the internal pressure of the first variable volume container is changed to the second variable volume container communicating with the second reaction container,
When the internal pressure becomes lower than the internal pressure of the variable volume container, the connecting rod moves in the opposite direction, and the reciprocating movement of the connecting rod is transmitted to the pump via an appropriate transmission mechanism, driving the pump. is configured to do so.

FIG. 3 shows an embodiment of a pump 29 equipped with the above converter and driven by the converter.

The sealed reaction vessel 41a contains a gas carrier that generates gas when heated, reversibly absorbs the gas when cooled, and therefore generates gas at higher pressure at higher temperature. The second reaction vessel 41 is filled with a chemical agent 42a.
b contains the same or different gas carrier 4 as above.
2b or an inert gas such as nitrogen or helium. These pair of reaction containers are connected to a variable volume container 44a via communication pipes 43a and 43b, respectively.
The cylinder chambers 46a and 46b are provided with pistons 45a and 45b, respectively, and the pistons are connected to each other by a piston rod 47 as the connecting rod.

In this embodiment, in order to cause the piston rod to reciprocate and use this reciprocating movement to drive the pump, a rack 4 is provided on the surface of the piston rod.
8 is formed, and a pinion 50 to which a crankshaft 49 is attached is engaged with this rack, and in this way, the reciprocating movement of the piston rod is transmitted to the plunger type pump 2 through the crankshaft.
As is well known, the pump 29 repeatedly sucks in and discharges water in cooperation with a valve mechanism (not shown), and as described above, the water is transferred to the piston 51 of the hot water storage tank via the connecting pipe 30. Water is forced to circulate through the heat collection plate.

In the solar water heater equipped with the above conversion device, the variable volume container 44 may be a bellows instead of a cylinder chamber with a piston, as described above, and may also be any other container as long as it has the same function. You can. These variable volume containers may be connected to the reaction container via a communication pipe as described above, but for example, gas may be carried inside the cylinder chamber or bellows by a wall that does not allow the gas carrier to permeate but allows the gas to pass therethrough. A closed container may be formed for filling the agent. For example, as described below, when using a metal hydride as a gas carrier, a porous wall made of porous sintered metal or porous resin does not allow the metal hydride to pass through, but allows hydrogen to pass through.

It is already known that certain metals and alloys exothermically absorb hydrogen to form metal hydrides, and that these metal hydrides reversibly and endothermically generate hydrogen. In the invention, such metal hydrides are preferably used as gas carriers.

Figure 4 shows the relationship between the reciprocal of the absolute temperature T and the logarithm of the hydrogen equilibrium decomposition pressure P of a metal hydride as an example of a gas carrier, and it is generally found that a nearly linear relationship holds for many metal hydrides. Are known. Therefore, according to an embodiment of the present invention, in FIG. 3 described above, the first reaction vessel 41a is filled with the first metal hydride MH1 having a lower hydrogen equilibrium decomposition pressure in the operating temperature range. , second
The reaction vessel 41b is filled with a second metal hydride MH2 having a higher hydrogen equilibrium decomposition pressure.
In this case, for example, keeping MH2 at a constant temperature,
By heating and cooling MH1, the piston rod can be reciprocated to drive the pump.

That is, to explain its operation based on Figure 4, when both the first and second reaction vessels are at the same temperature T1, MH2 has a higher hydrogen equilibrium decomposition pressure (Pb) at this temperature. , as shown in FIG. 3, the hydrogen pressure in the second cylinder chamber 46b is equal to the hydrogen pressure (Pa) in the first cylinder chamber 46a.
, and the piston rod 47 is located biased toward the first cylinder chamber 46a. Then, the first
When MH1 in the reaction vessel 41a is heated to a temperature T2 having a hydrogen equilibrium decomposition pressure (Pc) higher than MH2 at the temperature T1, the hydrogen pressure in the first cylinder chamber 46a increases to the second Since the piston rod is higher than the cylinder chamber of
7 moves to the second cylinder chamber 46b side. After this, the first reaction vessel 41a is cooled and the MH
When the temperature of the first cylinder is lowered to T1 again, the hydrogen pressures in the two cylinder chambers are reversed again, so the piston rod moves toward the first cylinder chamber as shown, and thus the piston rod performs a reciprocating motion.

As is clear from the above description of the operation, in the converter, at least the first reaction vessel containing the gas carrier needs to be heated and cooled by an external heat source. Further, the second reaction vessel may be alternately heated and cooled in a cycle opposite to that of the first reaction vessel, or may be maintained at a constant temperature by a heat source at a predetermined temperature.

As a means for heating and cooling the reaction vessel or maintaining it at a constant temperature, for example, a tube through which an external heating medium of a predetermined temperature is alternately or constantly passed through the vessel, or an electric resistance heating wire may be used. is possible,
Further, the temperatures T1 and T2 are appropriately selected depending on the available heat source. For example, a fixed temperature T1
is the outside air temperature or water temperature at room temperature, and T2 is the temperature obtained from an energy source such as electricity, gas, oil, solar heat, or waste heat.

In one embodiment of the solar water heater of the present invention, water in the hot water tank and the heat collecting plate is preferably used as a heat medium for heating and cooling the reaction vessel. That is, the first reaction vessel is disposed within the water channel of the heat collecting plate, and the second reaction vessel is disposed within the hot water storage tank. In such a device, when the heat collecting plate receives sunlight and the temperature of the water in the internal waterway increases, the hydrogen equilibrium decomposition pressure of MH1 becomes higher than that of MH2, as shown in Figure 4. As described above, the piston rod moves in one direction, the pump is driven by the crank mechanism, and water in the lower part of the hot water storage tank is supplied to the heat collecting plate. As a result, the water in the passages of the heat collecting plate is cooled down to the same temperature as the water in the hot water storage tank. At this time, as shown in FIG. 4, the hydrogen equilibrium decomposition pressure of MH1 is lower than that of MH2, so the piston rod moves in the opposite direction to the above, further driving the pump. In this way, the hot water in the collector plate is completely replaced by the water in the hot water tank, and the converter is stopped and the pump also stops working.

According to the above mechanism, even if the water temperature in the hot water storage tank fluctuates, as long as a heat source of temperature T2 at which MH1 becomes a hydrogen equilibrium decomposition pressure Pc greater than the hydrogen equilibrium decomposition pressure Pb is obtained, the device can be operated. It has the advantage that the operating temperature range is not particularly limited.

In the present invention, in addition to the above-mentioned metal hydrides, gas carriers include liquids that generate steam when heated in the operating temperature range and absorb steam when cooled, such as fluorocarbons, alcohol, acetone, etc. Furthermore, a combination of a metal hydride and these organic compounds can also be used. Therefore, in the above-described apparatus, the second reaction vessel 41b contains a metal hydride instead of a metal hydride. It is clear that it will work similarly even if filled with inert gas.

Furthermore, the transmission means for utilizing the above-mentioned reciprocating motion of the piston rod for driving the pump is not limited in any way, and may be any conventionally known mechanical means.

Next, FIGS. 5 and 6 respectively show the apparatus and its operation when the reaction vessel is filled with the same metal hydride. Note that the same members as in FIG. 4 are given the same reference numbers.

In this conversion device, solar heat is used as a heating medium for the first and second reaction vessels 41a and 41b. In this device, a pin 51 is provided on the piston rod 47, and an arm 52 is engaged with this pin. The arm is suitably pivoted on a stand 53 and can therefore be rotated about the pivot shaft 54 by the reciprocating movement of the piston rod. A cover 55 is attached to the end of the arm so that each reaction vessel can cover one of the reaction vessels when the arm is at the end of rotation, and each reaction vessel can receive solar radiation. It will be placed in an appropriate location. Alternatively, a transparent container may be provided connected to the hot water storage tank, and the water may be placed underwater within this container.

The operation of this device is as follows. That is, as shown in the figure, when the first reaction container 41a receives solar radiation, the second reaction container 41b is covered with the cover 55, and the temperature is T1 (point A), the reaction received by the solar radiation The metal hydride in the container is heated to a higher temperature T2 (point B) than the other metal hydride, the internal hydrogen equilibrium decomposition pressure increases, and the piston rod 47 moves in the direction of the solid line as described above, The arm pivots to uncover the second reaction vessel and cover the first reaction vessel. Then, contrary to the above, the first reaction vessel is cooled to a constant temperature T1, and the second reaction vessel is heated to a temperature T2 by sunlight, so the piston rod moves in the direction of the broken line and the second reaction vessel is cooled again. It will be covered with a cover. Therefore, the reciprocating motion of the piston rod can be used to drive the pump via the crank mechanism in the same way as described above.

FIG. 7 shows another embodiment of a pump equipped with a device for converting thermal energy into mechanical energy, in which an arm 61 is fixed to a piston rod 47 fixed between variable volume containers 44a and 44b, and an arm 61 is fixed on both sides of this arm. Rubber balls 62 and 63 as a pump are fixed to the pump, and these rubber balls have appropriate valves 64 and 6 inside, as shown in FIG.
5, and as the piston rod reciprocates,
When the rubber ball is compressed, it sucks in water and expels it. Of course, in this case, the arm may be connected to the piston of a plunger type pump as described above instead of the rubber ball.

FIG. 9 shows still another embodiment, in which an arm 72, which is supported by a shaft 71 as appropriate, is pivotally connected to a piston rod 47 between variable volume containers 44a and 44b, and fixed walls are provided on both sides of the arm. body 73
Rubber balls 75 and 76 are disposed between the piston rod and 74, and the pendulum movement of the arm accompanying the reciprocating movement of the piston rod is used to compress the rubber balls between the arm and the wall. It functions as a pump.

Various specific examples have been given above in which a conversion device from thermal energy to mechanical energy is connected to a pump and used to drive the pump, but in the solar water heater of the present invention, the means to use the conversion device to drive the pump is It goes without saying that there are no limitations and that various mechanical means other than those conventionally known can be used.

As described above, since the solar water heater of the present invention uses a flat plate-shaped hot water storage tank, no weight is added locally during installation, and it has excellent workability. One reaction vessel is filled with a gas carrier, and the other reaction vessel is filled with the same or different gas carrier or inert gas, and these reaction vessels are communicated with the volume variable vessel, and the gas carrier is filled with the gas carrier. By heating and cooling at least one filled reaction vessel to alternately make the gas pressure in the variable volume container communicating with this reaction vessel higher or lower than the gas pressure in the other variable volume container, Since the piston rod connected to the variable volume container pipe is reciprocated and used to drive the pump, strict temperature control is not required during its operation as long as a predetermined gas pressure difference is obtained between the variable volume containers. Water can be circulated without the need for it, and in particular, if solar heat or water in a water heater is used as a heating and cooling means for the reaction vessel, the pump can be driven without the need for paid energy.

[Brief explanation of drawings]

Fig. 1 is a schematic sectional view showing a conventional natural circulation solar water heater, Fig. 2 is a schematic sectional view showing a solar water heater of the present invention, and Fig. 3 is a schematic sectional view of a solar water heater of the present invention. The cross-sectional view shown in Fig. 4 is the third
A metal hydride fanto illustrating the operation of the apparatus shown in the figure.
Hotzf diagram; FIG. 5 is a perspective view of essential parts showing another embodiment of the pump driving device in the present invention; FIG. 6 is a Vand Hotzf diagram of another metal hydride for driving the pump in the present invention. , FIG. 7 is a schematic diagram showing another embodiment of the pump drive device, FIG. 8 is a schematic sectional view showing an example of the pump, and FIG. 9 is a schematic diagram showing yet another embodiment of the pump drive device. . 21... heat collection plate, 22... heat insulating material, 23... hot water storage tank, 26... connecting pipe, 29... pump, 30...
...Connecting pipe, 41a...First reaction container, 41b...
...Second reaction container, 43...Communication pipe, 44...Volume variable container, 47...Piston rod, 52...
Arm, 55...Cover, 61...Arm, 6
2, 63...Rubber ball, 72...Arm, 7
5,76...Rubber ball.

Claims (1)

[Claims] 1 A heat collection plate, a heat insulating material, and a flat hot water storage tank are stacked in this order from above, and the outlet of the heat collection plate and the upper part of the hot water storage tank are connected so that water can circulate, and the inlet of the heat collection plate and the lower part of the hot water storage tank are connected. and a solar water heater connected via a pump, the driving means of the pump generates gas when heated, reversibly absorbs the gas when cooled, and therefore A first closed reaction vessel filled with a gas carrier that generates gas at higher pressure at higher temperature, and a second closed reaction vessel filled with the same or different gas carrier or inert gas as above, first and second airtight variable volume containers each communicating with one of the reaction containers and whose volume changes in accordance with the internal pressure of the gas; and a rigid connecting rod that converts the volume change of the variable volume container into reciprocating motion, and when the first reaction container is heated, gas is generated from the gas carrier in the container, and the reaction container is heated. The connecting rod moves in one direction as the internal pressure of the first variable volume container communicating with the first variable volume container becomes higher than the internal pressure of the second variable volume container communicating with the second reaction container, and then the connecting rod moves in one direction. When the reaction container is cooled, the internal pressure of the first variable volume container becomes lower than the internal pressure of the second variable volume container communicating with the second reaction container, so that the connecting rod moves in the opposite direction. , A solar water heater characterized in that the pump is driven by the reciprocating motion performed by the connecting rod in this manner.