JPH0441271B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a long-distance heat transport method using metal hydrides.

(b) Conventional technology Conventionally, as shown in FIG. 3, heat transport methods for local energy such as solar heat collectors and geothermal heat are used to temporarily store heat collected in a heat collector 1 in a heat storage tank 2, Heat storage tank 2 and heat load 5 using heat medium pipes 3 and 4
This method circulated a heat medium between the two.

However, in methods using such heating media, large heat losses occur during transportation, resulting in a drop in the temperature of the heating medium, and relatively high-quality heat at the heat generation location becomes low-quality heat at the heat utilization location. This change was accompanied by a huge loss in terms of energy. Especially for the heat used in industrial processes, etc., the temperature level of the heat plays a very important role as well as the total amount of heat, and heat whose quality has deteriorated has no use value. It was necessary to apply highly effective insulation treatment.

Furthermore, in systems that utilize solar heat, the energy density is low, so the heat collection area becomes large, and even if the heat utilization points are not too far apart, the heating medium piping tends to become long. At the same time, as the solar heat collection temperature increases, the heat collection efficiency decreases, so it has been desired to have a heat transport system that keeps the heat collection temperature as low as possible and reduces the drop in temperature level. However, no method superior to heat transport using a heating medium has been proposed so far.

(c) Problems to be Solved by the Invention The present invention provides a long-distance heat transport method that uses metal hydrides to efficiently transport heat without reducing the temperature level from the heat generation point to the heat utilization point. The purpose is to provide.

(d) Means for solving the problem For this reason, the present invention provides two metal hydride containers each installed at a heat generation location and a distant heat utilization location, and connected by hydrogen piping. Then, the heat generated at the heat generation location is applied to one metal hydride container to generate hydrogen, which is sent to the heat utilization location via one hydrogen pipe, and the heat is extracted through one metal hydride container. At the same time, hydrogen is alternately returned from the other metal hydride container on the heat utilization site side to the other cooled metal hydride container on the heat generation site side via the other hydrogen piping using waste heat. It is characterized by being switched and executed continuously.

(e) Action In order to convert the heat generated at the heat generation point into hydrogen gas, which is chemical energy, using metal hydride and transport it, and to regenerate the heat at the heat utilization point, the utilized heat temperature level is changed to the generated heat temperature level. It is possible to make them exactly the same.

Furthermore, since heat transport is performed by hydrogen gas, heat loss during transport is limited to sensible heat loss of hydrogen gas. Therefore, the distance of the transportation piping is hardly a problem. At the same time, because the heat loss during transportation is small, there is no need for highly effective insulation treatment, and only insulation treatment for safety reasons (pipes near heat utilization points become hot due to the sensible heat of hydrogen gas). It becomes good.

(f) Examples Examples of the present invention will be described below with reference to the drawings.

FIG. 1 shows a conceptual configuration diagram of a heat transport method according to an embodiment of the present invention, and the same reference numerals as in FIG. 3 indicate the same or corresponding parts. In the figure, a heat transport unit 7 consisting of two metal hydride containers 7A and 7B containing metal hydride 6 is installed near a heat collector 1 at a heat generation location. On the other hand, in the heat utilization area, there are two metal hydride containers 9 containing metal hydride 8 near a heat load 5 such as a heating appliance.
A heat regeneration unit 9 consisting of A and 9B is installed. These metal hydride containers 7A, 9A and 7
Two hydrogen pipes 10 are connected between B and 9B.
A and 10B are arranged.

In addition, the metal hydride container 7A on the side where heat is generated,
7B, a heat medium pipe 12 connected to the heat collector 1 via a three-way switching valve 11 airtightly penetrates the external pressure-resistant vessel to flow the heat medium from the heat collector 1 to the inside, and the metal hydride 6 is piped to supply heat. Similarly, metal hydride containers 7A, 7
In B, a cooling water pipe 14 connected to a water source via a three-way switching valve 13 is installed so as to airtightly penetrate the pressure-resistant container and allow cooling water to flow inside to cool the metal hydride 6. There is.

On the other hand, the metal hydride container 9A on the heat utilization side,
9B, a heat medium pipe 16 connected to the heat storage tank 2 via a three-way switching valve 15 hermetically penetrates the pressure-resistant container to flow the heat medium inside, and transfers the heat generated from the metal hydride 8 to the heat storage tank. It is piped so that it can be taken out at 2. Similarly, the metal hydride container 9
In A and 9B, a heat medium pipe 18 connected to a waste heat source, which is a low-quality heat source, passes through the pressure vessel airtight through a three-way switching valve 17 to flow the heat medium inside, and heat the metal hydride 8. It is piped to supply the following.

With the above configuration, at the heat generation location, the three-way switching valves 11 and 13 connect the metal hydride container 7A to the heat collector 1 and the metal hydride container 7B to the cooling water source.
Switch. On the other hand, in the heat utilization area, the three-way switching valves 15 and 17 are switched to connect the metal hydride container 9A to the heat storage tank 2 and the metal hydride container 9B to the waste heat source. Thereby, the heat collected by the heat collector 1 is supplied to one metal hydride container 7A in the heat transport unit 7 installed near the heat collector 1. Here, the metal hydride filled in the metal hydride container 7A causes a hydrogen dissociation reaction (endothermic reaction) by supplying heat, and the generated hydrogen is transferred to the hydrogen pipe 10A.
The metal hydride container 9A in the thermal regeneration unit 9 is then transported to one metal hydride container 9A. The transported hydrogen reacts with the metal hydride 8 filled in the container 9A (exothermic reaction), and the reaction heat is recovered by the heat medium pipe 16 and supplied to the heat load 5 through the heat storage tank 2 (heat transportation process). Simultaneously with this heat transfer by hydrogen gas, a heat medium is supplied from a low-quality heat source (waste heat) to the other metal hydride container 9B in the heat regeneration unit 9, and the other metal hydride container 9B in the collection and transportation unit 7 is supplied with a heat medium from a low-quality heat source (waste heat) through the hydrogen pipe 10B. Hydrogen is returned to the metal hydride container 7B (regeneration process).

Next, the metal hydride containers 7A and 9A stored in the heat transport unit 7 and the heat regeneration unit 9 are
After a predetermined amount of hydrogen (effective hydrogen transfer amount) has been transported, the process switches to the regeneration process. At the same time, the metal hydride containers 9B and 7B that were in the regeneration process are switched to the heat transport process, and the metal hydride containers 9B and 7B in the heat regeneration unit 9
Heat at the collection temperature level is recovered from the In this way, by sequentially switching the containers 7A and 7B in the heat transport unit 7 and the containers 9A and 9B in the heat regeneration unit 9, the heat collected by the heat collector 1 is continuously transported to the heat load 5. can do.

The heat transport efficiency at this time will be compared with that of the conventional example using the heat medium shown in FIG. in this case,
Heat load 100000kcal/hr (temperature level 126~150
°C), heat transport distance 800m, transport heat medium amount 70l/
min, the thickness of the insulation material of the heat medium transport piping is 5 cm, and the total heat loss heat transfer coefficient of the piping is 0.1 kcal/hr・m・℃.

As a result, in heat transport using conventional heating medium, the third
As shown in the figure, the heat loss in the heat medium piping is 105000 kcal/hr for heat medium pipe 3, and 105000 kcal/hr for heat medium pipe 4.
It becomes 71000kcal/hr, reaching 176000kcl/hr round trip, and the thermal efficiency also drops to 0.36. In addition, the temperature level of the heating medium also decreases with heat loss, so the heat load
In order to supply a heating medium of 150℃, the heating medium temperature must be set to 175℃.
Must be at ℃.

On the other hand, in the heat transport of this embodiment using metal hydride, the heat loss in the hydrogen piping is small (heat loss of 2000 cal/hr or less), so heat transport can be performed with high efficiency. However, two heat transport units and a collection/regeneration unit are required for continuous operation.
Switching between two metal hydride containers reduces the thermal efficiency and therefore the overall efficiency is about 0.5. However, since there is no temperature drop due to heat transport, a heat collection temperature level of 150°C is sufficient, which increases the solar heat collection efficiency.

Thus, it can be seen that the heat transport using hydrogen gas in this example is superior in thermal efficiency to the heat transport using the conventional collector, and the heat collection temperature can also be set lower.

FIG. 2 shows an example of the case where the heat transport method according to the present invention is applied to a solar heat utilization device having a vast heat collecting area (for example, solar thermal power generation, solar heat utilization seawater desalination plant, etc.). As shown in the figure, heat transport units 21A, 21B, 21C are arranged in a plurality of heat collector groups 20A, 20B, 20C, respectively, and solar heat is effectively recovered by transporting heat through hydrogen piping 22 connected to each. can do.
Further, each hydrogen pipe 22 is concentrated in a heat regeneration unit 23, and after being regenerated into heat, it is supplied to a heat load 25 via a heat storage tank 24.

As described above, the heat transport method of the present invention can effectively utilize solar heat, but needless to say, it can be applied to all heat utilization devices that require long-distance heat transport.

(G) Effects of the Invention As explained above, according to the present invention, heat generated at a heat generating location is converted into hydrogen gas, which is chemical energy, using a metal hydride, and transported, and the heat is regenerated at a heat utilization location. In addition, the utilized heat temperature level can be exactly the same as the generated heat temperature level. Further, since heat transport is performed by hydrogen gas, heat loss during transport is limited to sensible heat loss of hydrogen gas, and therefore the distance of the transport piping does not matter much. At the same time, because the heat loss during transportation is small,
A heat-transporting method capable of highly efficient long-distance heat transport while maintaining the temperature level of the generated heat can be obtained without requiring a heat-insulating treatment with a high heat-insulating effect.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram of a heat transport method using metal hydrides according to one embodiment of the present invention, FIG. 2 is a conceptual diagram of a heat transport method using metal hydrides according to another embodiment of the present invention, and FIG. Figure 3 is a conceptual diagram of a conventional heat transport system using sensible heat as a heat medium. 1... Heat collector, 2, 24... Heat storage tank. 3, 4,
16, 18... Heat medium piping, 5, 25... Heat load,
6,8...metal hydride, 7,21A, 21B,
21C...Heat transport unit, 7A, 7B, 9A,
9B...Metal hydride container, 9,23...Heat regeneration unit, 10A, 10B...Hydrogen piping, 11,
13, 15, 17... Three-way switching valve, 12... Heat medium pipe, 14... Cooling water piping, 20A, 20B, 20
C... Heat collector group, 22... Hydrogen piping.

Claims (1)

[Claims] 1. At the heat generation location, a heat medium pipe that flows the heat medium from the heat source through the first switching valve and a cooling water pipe that flows the cooling water from the cooling water source through the second switching valve are installed inside the pressure vessel. Two metal hydride containers are installed with the metal hydride in an airtight penetrating arrangement, while a heat medium is flowed to the heat load via a third switching valve at the heat generation point and the distant heat utilization point. Two metal hydride containers are installed in which a heat medium pipe and a heat medium pipe through which a heat medium flows from a low-quality heat source through a fourth switching valve are arranged to pass through the pressure-resistant container together with the metal hydride in an airtight manner. , by connecting the metal hydride containers on the heat generation site side and the heat utilization site side through long-distance hydrogen piping, respectively, and switching each of the switching valves, a pair of metal hydrides connected through the hydrogen piping are connected. While a heat source and a heat load are connected to the container and hydrogen is transported from the heat generation site to the heat utilization site, a cooling water source and a low-quality heat source are connected to the other pair of metal hydride containers connected by the hydrogen piping. A long-distance heat transport method using a metal hydride, characterized in that the operation of returning hydrogen from the heat utilization point side to the heat generation point side is alternately and repeatedly performed by connecting a metal hydride.