JPS6248160B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat storage system using metal hydrides.

It is known that hydrogen storage metals such as TiFe.CaNi ₅ become metal hydrides when activated (hydrogenated) and absorb and devolatilize large amounts of hydrogen, emitting heat during the occlusion process and endothermic during the devolatilization process. ing. Utilizing this property of metal hydrides, it is possible to create a heat storage system that can store natural energy such as solar heat, wind power, industrial waste heat, etc. in the form of hydrogen gas and extract stable heat as needed. can.

A conventional heat storage system based on this principle, as shown in FIG. In the heat exchange section 5,
External heat source 6 such as solar heat and heat utilization device 7 such as a greenhouse
Heat exchange means 9 and 10 are provided which are connected to the radiator 8 inside via heat medium fluid pipes, and the hydrogen gas conduit 4 is provided with a stop valve 11.

This system is used to accumulate and utilize heat such as solar heat by transmitting the heat from the external heat source 6 to the metal hydride 1 in the holding container 2 through the heat transfer means 9 via the heat medium fluid to heat it. , hydrogen gas is devolatilized from the metal hydride 1, stored in the hydrogen gas storage tank 3 through the hydrogen gas conduit 4 with the stop valve 11 opened, and when heat is to be used, hydrogen gas is transferred from the hydrogen gas storage tank to the holding container 2. is caused to flow into the metal hydride 1, and the heat generated at this time is transferred to the heat medium fluid via the heat exchange means 10, and is released from the radiator 8 into the heat utilization device 7 for use.

In the conventional heat utilization method described above, the initial heat generated during hydrogen storage operation is used to raise the temperature of the metal hydride 1 itself and the metal hydride holding container 2, which has a large heat capacity and is configured as a pressure-resistant container. A fairly long transient characteristic region is created until heat at the target temperature is steadily extracted by the heat carrier fluid that conveys the heat to the utilization device 7.

From the perspective of heat utilization, it is advantageous to shorten the transient characteristic range as much as possible so that heat at the target temperature can be obtained steadily for a long period of time, and from the point of view of effective use of the limited calorific value of metal hydrides. That's desirable.

In view of the above-mentioned drawbacks of conventional heat storage systems using metal hydrides, the present invention provides a heat storage system using metal hydrides that eliminates transient characteristic regions and can always extract heat at a predetermined target temperature. The purpose is to

The present invention will be described in detail below based on drawings showing embodiments thereof.

FIG. 2 shows an embodiment in which the present invention is applied to the system described in FIG. Stop valve 1
1, an orifice 12 and a check valve 14 that can flow only in the direction from the hydrogen gas storage tank 3 to the metal hydride storage container 2 are connected in series in the direction from the metal hydride storage container 2 to the hydrogen gas storage tank 3. A check valve 13 that allows only flow is provided in parallel thereto. The orifice 12 is used to limit the amount of hydrogen gas flowing into the metal hydride holding container 2 and to control the amount of heat generated by hydrogen storage in the metal hydride. The rest of the configuration is similar to the conventional system described above.

The system configured as described above is used as follows. When the heat utilization device 7 requires heat,
When heat is obtained from an external heat source 6 such as solar heat, the heat given to the metal hydride by the heat exchange means 9 is recovered by the heat medium fluid from the other heat exchange means 10, and at the same time the remaining heat is removed. The metal hydride is heated to separate hydrogen gas, which is stored in a hydrogen gas storage tank 3 via a hydrogen gas conduit 4. At this time, hydrogen gas can freely pass through the check valve 13. When the heat utilization device 7 does not utilize heat, all the heat from the heat source is used for hydrogen devolatilization of the metal hydride.

Since the heat source 6 uses natural energy such as solar heat or wind power or factory waste heat, the amount of heat generated fluctuates depending on the weather, day and night, and the operating status of the factory. If the amount of heat generated by the heat source 6 is insufficient than the amount of heat used by the heat utilization device 7 or the amount of heat required to maintain the metal hydride 1 at a predetermined temperature when not in use, the temperature of the metal hydride decreases, As hydrogen is stored and the hydrogen gas pressure in the holding container 2 decreases, hydrogen gas is supplied from the hydrogen gas storage tank 3 to the metal hydride holding container 2 through the orifice 12, is stored in the metal hydride 1, and generates heat. A predetermined temperature can be maintained. In this case, since the check valve 13 is closed, the flow rate of hydrogen gas is appropriately controlled by the orifice 12, and excessive rise in pressure and overheating of the metal hydride holding container are prevented.

As described above, according to the present invention, the surplus heat of the heat source is stored in the form of hydrogen, whether the heat utilization device uses heat or not, and is released as heat when there is a shortage. It works as follows, and the heat from the heat source, which fluctuates frequently, can be converted into steady heat at a predetermined target temperature and used whenever necessary without passing through the transient characteristic range.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing an example of a conventional heat storage system using metal hydrides, and FIG. 2 is a system diagram of an embodiment of the present invention. 1... Metal hydride, 2... Holding container, 3...
Hydrogen gas storage tank, 4...Hydrogen gas conduit, 6...Heat source, 7...Heat utilization device, 12...Orifice, 1
3,14...Check valve.

Claims (1)

[Claims] 1. Holding a metal hydride in a container, heating it with an external heat source to devolatilize hydrogen gas, and transferring it to a hydrogen gas storage tank via a hydrogen gas conduit to accumulate it;
In a heat storage system in which hydrogen gas is caused to flow into the metal hydride holding container from the hydrogen gas storage tank through the hydrogen gas conduit as necessary, the hydrogen gas is occluded by the metal hydride, and the reaction heat generated at that time is utilized. A check valve that allows flow only in the direction from the metal hydride holding container to the hydrogen gas storage tank is connected in series with an orifice in the conduit and a check valve that allows flow only in the direction from the hydrogen gas storage tank to the metal hydride holding container. A heat storage system characterized by being installed in parallel with these.