JP2001272129A - Refrigerating unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low pressure type refrigerating system using carbon dioxide. SOLUTION: A freezer 1 is equipped with activated charcoals 2 and 3 as adsorbents, a compressor 4 which desorbs carbon dioxide from one side of the activated charcoals 2 and 3 and also makes the other side desorb carbon dioxide, and heat exchangers 5 and 6 which are switched and connected to the activated charcoals 2 and 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-pressure refrigeration system using activated carbon as an adsorbent and utilizing an endothermic reaction when desorbing carbon dioxide adsorbed on activated carbon.

[0002]

2. Description of the Related Art Among known refrigeration systems,
A typical example using carbon dioxide uses carbon dioxide as a refrigerant. In such a refrigerating apparatus, it is necessary to compress carbon dioxide with a compressor and raise the pressure to about 10 MPa, and it is necessary to make the compressor and the heat exchanger pressure-resistant.

[0003]

However, in particular, heat exchangers such as condensers and evaporators generally have a fin structure made of aluminum, copper, or the like, and need to be changed to a structure suitable for withstanding pressure. For this reason, it is necessary to take measures such as increasing the thickness of the pipe through which the refrigerant passes, and there is a concern that the performance of the heat exchanger will be reduced, and as a result, the performance of the refrigeration apparatus will be reduced.

The present invention has been made to solve the above problems. An object of the present invention is to provide a low-pressure refrigeration system using carbon dioxide.

[0005]

A refrigerating apparatus according to the present invention uses activated carbon as an adsorbent for carbon dioxide. In one aspect, activated carbon is desorbed from activated carbon having carbon dioxide adsorbed thereon. Is cooled, a heat medium is supplied to the cooled activated carbon to cool the heat medium, and the cooled heat medium is supplied to a heat load to perform cooling.

The inventors of the present application have intensively studied a system capable of performing a refrigerating operation without increasing the pressure of carbon dioxide as in the conventional example, and have moved away from using carbon dioxide directly as a refrigerant and indirectly using carbon dioxide as a refrigerant. I thought about using it. That is, the present inventors have conceived a system that performs a refrigerating operation by utilizing an endothermic reaction when desorbing carbon dioxide from an adsorbent. Then, when a material suitable as an adsorbent for carbon dioxide in the present invention was examined, it was found that activated carbon was appropriate as an adsorbent from the viewpoint of an endothermic reaction. Activated carbon can be cooled by desorbing carbon dioxide from activated carbon in a state where carbon dioxide is adsorbed, and the heating medium can be cooled by supplying a heating medium to the activated carbon. Cooling can be achieved by supplying the medium to a thermal load.
Therefore, cooling can be performed without compressing carbon dioxide and the heat medium to a high pressure.

[0007] In another aspect, the refrigeration apparatus according to the present invention includes:
First and second activated carbon for adsorbing / desorbing carbon dioxide;
A compressor having a suction side connected to one of the first and second activated carbons for desorbing carbon dioxide from the one side, and a discharge side connected to the other of the first and second activated carbons to supply compressed carbon dioxide to the other side; First switching means for switching and connecting the compressor and the first and second activated carbons, a first heat exchanger connected to one of the first and second activated carbons for removing heat from a heat load, A second heat exchanger connected to the other for cooling the other; and a second switching means for switching between the first and second activated carbon and the first and second heat exchangers.

First, it is assumed that the adsorption of carbon dioxide on the first activated carbon has been completed. In this case, the suction side of the compressor is connected to the first activated carbon. Thereby, carbon dioxide can be desorbed from the first activated carbon, and the first activated carbon is cooled. By connecting the first activated carbon with the first heat exchanger, heat is removed from the heat load around the first heat exchanger, and the first activated carbon is removed from the first heat exchanger.
The surroundings of the heat exchanger can be cooled. At this time, the discharge side of the compressor is connected to the second activated carbon, and pressurized carbon dioxide is supplied to the second activated carbon. Thereby, carbon dioxide can be adsorbed on the second activated carbon, and the temperature of the second activated carbon rises accordingly. Then, the second heat exchanger is connected to the second activated carbon, and the second activated carbon is cooled. Thereby, a large amount of carbon dioxide can be adsorbed on the second activated carbon. After the adsorption of carbon dioxide to the second activated carbon is completed and the cooling by the first activated carbon is completed, the first switching means is operated to connect the suction side of the compressor to the second activated carbon,
The discharge side of the compressor is connected to the first activated carbon, the second switching means is operated to connect the second activated carbon to the first heat exchanger, and the first activated carbon is connected to the second heat exchanger. Thereby, cooling can be performed using the second activated carbon, and carbon dioxide can be adsorbed on the first activated carbon. As described above, the periphery of the first heat exchanger can be continuously cooled using the first and second activated carbons.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2,
One embodiment of the present invention will be described. 1 and 2 are schematic configuration diagrams of a refrigeration apparatus according to one embodiment of the present invention.

A refrigeration apparatus according to the present invention uses activated carbon as an adsorbent for carbon dioxide and performs a cooling action by utilizing an endothermic reaction in which the temperature of activated carbon is reduced by desorbing carbon dioxide adsorbed on activated carbon. It is.

More specifically, the refrigeration apparatus according to the present invention comprises:
Activated carbon, a desorption means for desorbing carbon dioxide from the activated carbon, and a heat exchanger for cooling a heat load by utilizing a temperature decrease of the activated carbon.

The inventors of the present application have intensively studied a system capable of performing a refrigeration operation without increasing the pressure of carbon dioxide as in the conventional example, and have moved away from using carbon dioxide directly as a refrigerant and indirectly using carbon dioxide as a refrigerant. I thought about using it. That is, the present inventors have conceived a system that performs a refrigerating operation by utilizing an endothermic reaction when desorbing carbon dioxide from an adsorbent.

[0013] Then, when a material suitable as an adsorbent for carbon dioxide in the present invention was examined, it was found that activated carbon was appropriate as an adsorbent from the viewpoint of endothermic reaction.

By desorbing carbon dioxide from activated carbon by the above desorption means, the temperature of the activated carbon is lowered. By supplying a heat medium such as water or alcohol to the activated carbon, the heat medium is cooled, and by guiding the cooled heat medium to the heat exchanger, the periphery of the heat exchanger can be cooled.

As described above, since the heat medium is cooled by the activated carbon having a lowered temperature, and the heat medium is merely guided to the heat exchanger,
There is no need to compress the heating medium to a high pressure. Further, since it is only necessary to efficiently adsorb carbon dioxide on activated carbon, it is not necessary to compress carbon dioxide to a high pressure as in the conventional example. Therefore, the refrigeration apparatus can be of a low pressure type.

A specific configuration example of the refrigeration apparatus 1 according to the present invention will be described below with reference to FIGS.

As shown in FIGS. 1 and 2, a refrigeration system 1 of the present invention comprises a set of activated carbons 2 and 3 and a compressor 4
And heat exchangers 5 and 6.

The activated carbons 2 and 3 adsorb and desorb carbon dioxide, and are connected to the compressor 4 via pipes 14 to 16. A four-way switching valve 7 is provided between the activated carbons 2 and 3 and the compressor 4. By operating the four-way switching valve 7, the activated carbons 2 and 3 and the compressor 4 can be switched and connected.

The activated carbons 2 and 3 are connected to the heat exchangers 5 and 6 via pipes 17 to 28. Between the activated carbons 2, 3 and the heat exchangers 5, 6, four-way switching valves 8 to 11 are provided, and by operating the four-way switching valves 8 to 11, the activated carbons 2, 3 and the heat exchangers 5, 6 can be switched.

In FIG. 1, the suction side of the compressor 4 is connected to the activated carbon 2, and the discharge side of the compressor 4 is connected to the activated carbon 3. Thereby, carbon dioxide can be sucked from the activated carbon 2 to desorb the carbon dioxide, and pressurized carbon dioxide can be supplied to the activated carbon 3 to efficiently adsorb the carbon dioxide. The compressor 4 only needs to be capable of pressurizing carbon dioxide to about 2 MPa, and may be a compressor used in a conventional air conditioner, refrigerator or the like.

In FIG. 1, the heat exchanger 5 is connected to the activated carbon 2 on the side where the temperature is lowered by the desorption of carbon dioxide, and has a function of cooling the surroundings. A heat medium such as water or alcohol is sealed in a first path connecting the heat exchanger 5 and the activated carbon 2. A pump 12 is provided in the first path, and the heat medium circulates in the first path by the pump 12.

In FIG. 1, the heat exchanger 6 is connected to the activated carbon 3 on the side where carbon dioxide is adsorbed and the temperature rises, and has a function of cooling the activated carbon 3. Heat exchanger 6 and activated carbon 2,
A heat medium such as water or alcohol is also sealed in the second path connecting the third medium 3 and the second medium. A pump 13 is provided in the second path, and the heat medium circulates in the second path by the pump 13.

Next, the operation of the refrigeration apparatus 1 having the above configuration will be described. First, it is assumed that the adsorption of carbon dioxide on activated carbon 2 has been completed. In this case, as shown in FIG.
The suction side of the compressor 4 is connected to the activated carbon 2. Thereby, carbon dioxide can be desorbed from the activated carbon 2,
Activated carbon 2 is cooled. Specifically, the temperature of the activated carbon 2 is about −10 ° C. to 5 ° C.

A heat medium is supplied to the activated carbon 2 by a pump 12 through pipes 17 to 22, and the heat medium is supplied to the activated carbon 2.
Cooled by. The activated carbon 2 is connected to the heat exchanger 5 as shown in FIG. 1, and the heat medium cooled in the heat exchanger 5 flows. At that time, the heat medium can take heat from the heat load around the heat exchanger 5 and cool the periphery of the heat exchanger 5.

At this time, the discharge side of the compressor 4 is connected to the activated carbon 3, and pressurized carbon dioxide is supplied to the activated carbon 3. Specifically, carbon dioxide at a pressure of about 1 to 2 MPa is supplied. Thereby, carbon dioxide can be adsorbed on the activated carbon 3.

The temperature of the activated carbon 3 rises with the adsorption of carbon dioxide. Specifically, the temperature of the activated carbon 3 can rise to about 30C to 40C. However, the lower the temperature of the activated carbon 3, the greater the amount of carbon dioxide adsorbed.
To cool.

In order to cool the activated carbon 3, as shown in FIG. 1, a heat medium (cooling water) is passed through pipes 23 to 28 connecting the activated carbon 3 and the heat exchanger 6, and the heat generated by the activated carbon 3 is passed through the pipe. Let them rob. Thereby, the temperature of the activated carbon 3 can be lowered to about 25 ° C. to 30 ° C., and a large amount of carbon dioxide can be adsorbed on the activated carbon 3.

After the adsorption of carbon dioxide on the activated carbon 3 is completed and the cooling by the activated carbon 2 is completed, the four-way switching valve 7 is operated to connect the suction side of the compressor 4 to the activated carbon 3 as shown in FIG. Then, the discharge side of the compressor 4 is connected to the activated carbon 2, and the four-way switching valves 8, 10 are operated to connect the activated carbon 3 to the heat exchanger 5, and to connect the activated carbon 2 to the heat exchanger 6.

As a result, the activated carbon 3 can be cooled to adsorb the pressurized carbon dioxide on the activated carbon 2. The above operation is repeated. Therefore, the surroundings of the heat exchanger 5 can be continuously cooled using the activated carbons 2 and 3.

Although the embodiment of the present invention has been described above, the embodiment disclosed herein is illustrative in all aspects and should not be considered as being restrictive. The scope of the present invention is defined by the appended claims, and includes all modifications within the scope and meaning equivalent to the claims.

[0031]

As described above, according to the refrigerating apparatus of the present invention, cooling is performed by utilizing an endothermic reaction when desorbing carbon dioxide from activated carbon. There is no need to compress the (refrigerant) to a high pressure. Therefore, the refrigeration apparatus can be operated at a lower pressure than in the conventional example, and it is not necessary to change a heat exchanger such as a condenser or an evaporator to a structure suitable for withstanding pressure. As a result, a high-performance low-pressure refrigeration system using carbon dioxide can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating a first operation of a refrigeration apparatus according to one embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a second operation of the refrigeration apparatus according to one embodiment of the present invention.

[Explanation of symbols]

1 Refrigeration equipment, 2, 3 activated carbon, 4 compressors,
5, 6 heat exchanger, 7-11 4-way switching valve, 12, 13
Pump, 14-28 piping.

Claims (2)

[Claims] 1. Activated carbon is used as an adsorbent for carbon dioxide, the activated carbon is cooled by desorbing the carbon dioxide from the activated carbon adsorbing the carbon dioxide, and a heat medium is supplied to the cooled activated carbon. A refrigeration apparatus comprising: cooling the heat medium; and supplying the cooled heat medium to a heat load to perform cooling. 2. A first and second activated carbon for adsorbing / desorbing carbon dioxide, and a suction side is connected to one of the first and second activated carbons to desorb the carbon dioxide from one of the first and second activated carbons, and a discharge side is connected to the first and second activated carbon.
A compressor connected to the other of the second and the second activated carbon and supplying the carbon dioxide after compression to the other; a first switching means for switching and connecting the compressor and the first and the second activated carbon; A first heat exchanger connected to one of the second activated carbons to remove heat from a heat load; a second heat exchanger connected to the other of the first and second activated carbons to cool the other; and A refrigeration apparatus comprising: first and second activated carbons; and second switching means for switchingly connecting the first and second heat exchangers.