JPH056119B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a hydrogen storage/release type heat exchanger,
Specifically, the present invention relates to a hydrogen storage/release type heat exchanger that has been improved so that the entire inner container for storing hydrogen storage metal or the storage metal itself can be easily replaced as necessary.

Hydrogen storage metals have the property of storing hydrogen in the form of metal hydride, and also have the property of generating heat when absorbing hydrogen and absorbing heat when releasing hydrogen, so they can be used in various applications (heat storage tanks, heat pumps, hydrogen gas storage, etc.). It is expected to be applied to separation and purification equipment (separation and purification equipment, etc.), and for example, it is being considered to use a container filled with hydrogen storage metal as a heat exchanger in a heat pump.

FIG. 1 is a schematic diagram illustrating a hydrogen storage/release type heat exchanger used in the heat pump system, and FIG. 2 is a cross-sectional view taken along the line - in FIG. 3 is a metal filling tube for hydrogen storage (hereinafter referred to as filling tube),
4 indicates a collection header, and 6 indicates a heat collector or a heat radiator, respectively.

The heat exchanger 1 has a plurality of filling tubes 3 arranged in parallel in a shell 2, ends of the filling tubes 3 in the same direction are connected to a collection header 4, and a hydrogen conduit 5 is connected to the collection header 4. It consists of
And the heat medium inlet pipe 7a and the outlet pipe 7 of the shell 2
b is connected to a heat collector or radiator 6 via a pipe line 8.

In the heat exchanger 1 having the above configuration, a low to medium temperature heat medium L is introduced into the shell 2 from the inlet pipe 7a and led out from the outlet pipe 7b, while H ₂ is introduced from the hydrogen conduit 5.
When hydrogen is blown into hydrogen storage metal M,
The temperature of the hydrogen storage metal M increases due to the heat generated by the hydrogen storage reaction, and the heating medium L is heated by heat transfer from the wall of the filling tube 3. The heated heat medium L is supplied from the outlet pipe 7b through the pipe 8 to the radiator 6, warms the environment, and then flows back to the heat exchanger 1.

On the other hand, in a state where hydrogen storage metal M stores hydrogen (state of metal hydride), heat exchanger 1
While the heating medium L at room temperature to high temperature is passed through the tube, the pressure inside the filling tube 3 is reduced by operating a suction pump (not shown) attached to the end of the hydrogen conduit 5 (on the left side of the figure), and the metal When the pressure is lower than the dissociation pressure of the hydride, H ₂ is released from the metal hydride. At this time, the hydrogen storage metal M is cooled by heat absorption accompanying the hydrogen release reaction.
The cooled heat medium L is introduced from the outlet pipe 7b via the conduit 8 into the heat collector 6, where it cools the environment, absorbs heat, and returns to the heat exchanger. In the heat pump, heating is performed in the cycle shown in FIG. 4, and cooling is performed in the cycle shown in FIG. 5, by utilizing the heat radiation and heat absorption effects of the hydrogen storage metal as described above.

By the way, some hydrogen storage metals used in heat exchangers have various equilibrium dissociation pressure-dissociation temperature curves. For example, LaNi ₅ has a temperature of 2atm-24℃,
Mg ₂ Ni has a temperature of 3 atm - 300℃, and FeTi has a temperature of 3.5 atm - 25℃. Generally, for heating purposes, the temperature reached during hydrogen storage (hydrogen filling) is high, and for cooling purposes, the temperature reached during hydrogen dissociation is high. It is said that low temperature is suitable. However, no hydrogen storage metal has been proposed that has a sufficiently high temperature during hydrogen storage and a sufficiently low temperature during hydrogen dissociation, ie, one that can be used in both heating and cooling operations. Therefore, in a heat pop system for cooling and heating, a heat exchanger filled with hydrogen storage metal for heating and a heat exchanger filled with hydrogen storage metal for cooling operation are prepared, and the heat exchanger filled with hydrogen storage metal for cooling operation is prepared. It is necessary to select which heat exchanger to use. As a result, not only is the equipment uneconomical, but each time a heat exchanger is replaced, complicated work such as separation and connection of piping systems and transportation of the heat exchanger must be performed.

In addition, used storage metal whose hydrogen storage capacity has decreased needs to be replaced with new storage metal at an appropriate time in preparation for the next use, but to do so, the heat exchanger must be disassembled, and it is difficult to replace it. It required a lot of effort.

It should be noted that the hydrogen storage metal becomes pulverized over the course of use and its hydrogen storage capacity decreases, so in this case as well, it becomes necessary to replace the storage metal, causing the same problem as described above.

As a result of research conducted to solve the above-mentioned drawbacks, the present invention has found that, as long as the heat exchanger has a structure in which the hydrogen storage metal storage part, that is, the part corresponding to the filling tube in the illustrated example, can be easily taken out and replaced, the above-mentioned I came up with an idea that could eliminate all of the shortcomings of . The present invention was completed as a result of further research in order to embody these ideas, and the gist of the present invention is based on a pressure vessel for pressurizing hydrogen gas and an inner container disposed inside the pressure vessel through an air gap. The hydrogen gas pressurizing container is composed of a lid body in which a hydrogen conduit and a heat medium pipe are arranged, and a pressure vessel main body, and the inner container is provided with a fan for promoting heat transfer on the outer peripheral surface. The tube for the heat medium flow path is arranged by being folded back at least once in the vertical direction, and the folded tube is partitioned approximately horizontally between the folded tubes with a partition shelf, so that the inside of the inner container can be arranged in the vertical direction. The partitioned space is filled with a metal for absorbing hydrogen, and at least a part of the side wall surface of the inner container perpendicular to the partition shelf is constituted by a removable filter member, and the partitioned space is filled with a metal for absorbing hydrogen. The flow path pipe and the heat medium pipe are removably connected to each other outside the inner container, and the hydrogen pipe is provided so as to be open in the space.

Hereinafter, the configuration and effects of the present invention will be explained in detail with reference to the drawings.

FIG. 3 is a partially cutaway exploded perspective view illustrating a heat exchanger according to the present invention, where 1a is a heat exchanger, 2a is a
9 is a pressure vessel for pressurizing hydrogen gas (hereinafter referred to as pressure vessel), 3a is an inner container for filling with metal for hydrogen storage, and 9
1 is a lid, 10 is a filter member, 11 is a heat medium flow pipe (hereinafter referred to as a heat medium pipe) 12 is a partition shelf, 3
indicate fins for promoting heat transfer.

The inner container 3a has partition shelves 12 provided approximately horizontally within a box body having openings on two opposing sides (front right side and rear left side in the figure), and heat medium pipes with fins 13 in each partition space. A plurality of heat medium pipes 11 are arranged, and the heat medium pipes 11 are bent vertically at least once (three times in the illustrated example) via a curved pipe 11a, and the partition shelf 12 is placed between them. The heat medium pipes 11 include one collective heat medium pipe 1 at the inlet B to the inner container and the outlet A from the inner container.
1b, and is connected to a heat medium pipe outside the system. The fins 13 are provided to promote heat transfer, and may have any shape or structure. For example, rectangular fins may be provided with irregularities to improve heat transfer performance. It is possible. Further, in the illustrated example, the heat medium pipe 11b is fixed to the lid 9, and the heat medium pipe 11b is connected to the inlet portion B through the union joint 15.
Although an example is shown in which it is detachably connected to the output section A, the connection structure and the connection location itself are not limited to the illustrated example.

Further, the heat medium pipe 11b is fixed through the lid 9 to which the hydrogen conduit 14 is connected. Furthermore, the inner container 3a
is filled with hydrogen storage metal M so as to fill the partitioned space, and a filter member 10 is attached to at least one of the openings on both sides.
When such an inner container 3a is housed in a pressure vessel 2a and the lid 9 and the pressure vessel 2a are fastened together by flange connection or the like, a heat exchanger 1a is constructed.

Using the heat exchanger with the above configuration, the hydrogen conduit 1 is heated while flowing the low to medium temperature heat medium L in the same manner as in the example shown in FIG.
When hydrogen is introduced from 4, the filling metal M generates heat due to the heat of hydrogen storage, and the heating medium L is heated through the finned heating medium pipe 11. On the other hand, while the heating medium L at room temperature to high temperature is flowing, the filling metal M generates heat due to the heat of hydrogen storage. When hydrogen is released from M, the temperature of the filling metal M is lowered due to heat absorption during hydrogen storage, and the heating medium L is cooled.

Heating or cooling is performed using the heat medium L heated or cooled in this way.

In the above heat exchanger, when switching between cooling and heating, or when the hydrogen storage metal M in the inner container 3 is pulverized and device efficiency decreases, it becomes necessary to replace the hydrogen storage metal M. In this case, first, the lid 9 and the pressure vessel 2a are uncoupled. Next, after removing the inner container 3a integrated with the lid body 9 from the pressure vessel, the connection by the union joint 15 is released to separate the lid body 9 and the inner container 3a, and a separately prepared inner container (a new hydrogen storage metal Replace with one filled with On the other hand, when replacing the used hydrogen storage metal M in the inner container 3a, after removing the filter member 10, the used hydrogen storage metal M is taken out and replaced with a new one.

The filter member may be of any material as long as it blocks the passage of the hydrogen storage metal M and allows the passage of hydrogen gas, but a typical example is a sintered metal with vents of about 2 μm. An example is a manufactured filter.

Further, the reason why the partition shelf 12 is provided as an essential component in the present invention is as follows. That is, the inner container 3
The hydrogen storage metal M filled in a is repeatedly shaken by the flow of hydrogen gas generated as hydrogen is stored and released, or by vibrations applied to the heat exchanger from the outside. is compressed downward by its own weight, creating an extreme difference between the packing density on the lower side and the packing density on the upper side. Then, heat transfer efficiency is required on the upper side, and the problem arises that on the lower side, compaction progresses too much, resulting in insufficient hydrogen gas flow and poor occlusion/desorption efficiency.

However, if a partition shelf 12 is used between the folded heat medium pipes 11 as shown in the figure, the above-mentioned problems will be eliminated, and hydrogen storage and release will be carried out efficiently and heat will be efficiently stored and released in each partitioned compartment. An exchange will take place.

The structure of the finned heat transfer tube and the inner container is not unique, and the finches and container used in general heat exchangers can be modified and used. In addition, it is preferable to cover the inner and outer walls of the pressure vessel or the outer circumferential surface of the inner vessel, excluding the filter surface, with a heat insulating material, since sensible heat loss to the outside of the pressure vessel can be reduced.

The present invention is configured as described above, and the inner container can be easily replaced as necessary, so switching between heating and cooling operations or replacing the inner container when the hydrogen storage capacity decreases can be done with little effort. In addition, the hydrogen storage metal can be easily removed by simply removing the filter member of the inner container, so a special inner container filled with hydrogen storage metal for heating or cooling hydrogen storage metal is prepared. There is no need to do this, and equipment waste can be avoided.
Moreover, the filling density of the hydrogen storage metal within the device can be maintained uniformly in the vertical direction.
Hydrogen storage/release and heat exchange can be carried out efficiently as a whole.

Moreover, even when the capacity of the inner container is increased, the vertical packing density can be maintained evenly by the partition shelf, so it can be effectively used as a particularly large-sized facility with a large hydrogen storage and release capacity.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing a conventional hydrogen storage/release type heat exchanger, Fig. 2 is a cross-sectional view taken along the line - in Fig. 1, and Fig. 3 is a hydrogen storage/release type heat exchanger of the present invention. 4 and 5 are graphs showing the relationship between hydrogen dissociation pressure and hydrogen dissociation temperature of metal. 1, 1a: heat exchanger, 2, 2a: pressure vessel,
3: Filling tube, 3a: Inner container, 10: Filter, 11: Pipe body for heat medium flow path, M: Metal for hydrogen storage, L: Heat medium.

Claims (1)

[Claims] 1 Consists of a pressure vessel for pressurizing hydrogen gas and an inner container disposed inside the pressure vessel via air, and the hydrogen gas pressurizing vessel consists of a lid body in which a hydrogen conduit and a heat medium pipe are arranged, and a pressure vessel. On the other hand, the inner container has at least one pipe body for a heat medium flow path provided with heat transfer promoting fins on the outer peripheral surface in the vertical direction.
The interior of the inner container is divided vertically by dividing the folded tubes in a substantially horizontal direction with a partition shelf, and the divided space is used for hydrogen storage. filled with metal, and at least a portion of a side wall surface of the inner container perpendicular to the partition shelf is configured with a removable filter member,
The heat medium flow pipe and the heat medium pipe are detachably connected to each other outside the inner container, and the hydrogen conduit is provided so as to be open to the space. Hydrogen storage/release heat exchanger.