JPH06323685A - Method and device for generation of cold heat - Google Patents

Abstract

PURPOSE:To provide method and device for generation of cold heat which can take out easily cold heat in a freezing temperature range. CONSTITUTION:A pair of containers 1 and 3 formed of a low pressure side container which is charged with metal hydride of a low hydrogen balance pressure and a high pressure side container which is charged with metal hydride of a high hydrogen balance pressure and another pair of containers 2 and 4 are communicated mutually through hydrogen conduits 8a and 8b, so that a hydrogen stream may be switched to change its flowing direction alternately by a compressor 5 between the pairs of containers 1 and 3, and 2 and 4. In accordance with this switching, a heat exchanger of the low pressure side container which is on a hydrogen releasing side and a heat exchanger of the high pressure side container which is on a hydrogen absorbing side are connected, a heat exchanger of the low pressure side container on a hydrogen absorbing side and a heat exchanger of a heat releasing part are connected, and further a heat exchanger of the high pressure side container on a hydrogen releasing side and a heat exchanger of a cooling load 13 are connected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cold heat generating method and a cold heat generating apparatus for continuously taking out cold heat from a metal hydride.

[0002]

2. Description of the Related Art It is known that certain metals and alloys exothermically absorb hydrogen to form a metal hydride, and this metal hydride reversibly releases hydrogen. Here, the metal hydride becomes a metal when it is dehydrogenated, and the metal hydride is also included in this case.

As a conventional method for controlling an air conditioner using a metal hydride, for example, Japanese Patent Publication No. 58-19954.
There is one disclosed in the publication. That is, a compressor is provided between two heat exchange type metal containers containing different amounts of metal hydride, the flow of hydrogen gas is repeatedly reversed by this compressor, and the hydrogen is released through the metal container. It is configured to be cooled and heated via a metal container in the process of storing hydrogen.

[0004]

However, in the conventional method, when the cold heat in the freezing temperature range (-20 ° C. or less) is taken out, there are the following problems.

First, according to the temperature-pressure characteristics of different amounts of metal hydrides disclosed in Japanese Patent Publication No. 58-199554, the hydrogen pressure on the side for taking out cold heat becomes extremely low in the freezing temperature range. Therefore, if low-pressure hydrogen in the freezing temperature range is sucked by the compressor to compress the hydrogen to reverse the hydrogen flow, the compression ratio of the compressor becomes extremely large, and the compressor must be rotated at high speed. However, there is a problem that operating conditions become severe and operation of the compressor becomes difficult due to the performance of the compressor.

Furthermore, when trying to take out cold heat at a low temperature of -50 ° C., the hydrogen pressure at the cold heat take-out side becomes even lower, so there is a limit to the high speed rotation of the compressor, and sufficient pressurization is possible. However, there was a problem that low-temperature cold heat of -50 ° C level could not be taken out continuously. In this case, it is conceivable to use a metal hydride that has a relatively high hydrogen pressure on the side that takes out cold heat in the freezing temperature range. Compounds in the freezing temperature range (-20 ° C
A new problem arises in that a cooling means is required as described below.

Therefore, an object of the present invention is to provide a cold heat generating method and a cold heat generating device which can easily take out cold heat in a freezing temperature range.

[0008]

According to the invention of claim 1, a low pressure side container filled with a metal hydride having a low equilibrium hydrogen pressure characteristic together with a heat exchanger and a metal hydride having a high equilibrium hydrogen pressure characteristic together with a heat exchanger are provided. A pair of containers consisting of the filled high-pressure side container are connected to each other by a hydrogen conduit via two sets of compressors, and one pair of the two sets of containers transfers hydrogen to the other pair of containers by the compressor. The cold heat generated in the low pressure side container of the one pair of containers by being forcibly transferred is supplied to the high pressure side container of the other pair of containers via the heat exchanger. While cooling with, while radiating the occlusion heat generated in the low pressure side container of the other pair of containers, the desired cold heat generated in the high pressure side container of the one pair of containers is the heat exchanger. Before the first cycle to take out via Cold heat generated in the low-pressure side container of the other pair of containers by switching the hydrogen transfer by the compressor from the other pair of containers to the one pair of containers is the one pair via the heat exchanger. While supplying and cooling through the heat exchanger into the high pressure side container of the container, while radiating the occlusion heat generated in the low pressure side container of the one pair of containers, the other pair of containers The desired cold heat generated in the high-pressure side container is alternately repeated with the second cycle for taking out the desired cold heat via the heat exchanger, and the desired cold heat is continuously supplied to the cooling load.

According to a second aspect of the present invention, there is provided a low pressure side container filled with a heat exchanger and a metal hydride having a low equilibrium hydrogen pressure characteristic, and a high pressure side container filled with a heat exchanger and a metal hydride having a high equilibrium hydrogen pressure characteristic. From a pair of vessels consisting of, a low-pressure side container filled with a metal hydride having low equilibrium hydrogen pressure characteristics together with a heat exchanger, and a high-pressure side vessel filled with metal hydride having high equilibrium hydrogen pressure characteristics together with a heat exchanger. The other pair of containers, the hydrogen conduit provided by connecting the one pair of containers and the other pair of containers, and the first switching for switching the transfer of hydrogen provided in the hydrogen conduit. A valve and one compressor for forcibly transferring hydrogen, a heat radiating section including a heat exchanger for radiating heat, a cooling load including a heat exchanger, and a switching connection between the heat exchangers as appropriate. Heat medium piping and By switching the second switching valve provided on the heat medium pipe and the first switching valve, hydrogen is forcibly transferred by the compressor from the one pair of vessels to the other pair of vessels. A first switching control means that alternately repeats a first cycle and a second cycle in which the compressor forcibly transfers hydrogen from the other pair of containers to the one pair of containers; and the second cycle. At the time of the first cycle by switching the switching valve, the heat exchanger of the low pressure side container of the one pair of containers and the heat exchanger of the high pressure side container of the other pair of containers are connected to each other, and the other pair is connected. Connecting the heat exchanger of the low-pressure side container of the container and the heat exchanger of the heat dissipation unit, and connecting the heat exchanger of the high-pressure side container of the one pair of containers and the heat exchanger of the cooling load, respectively. To switch to the second cycle Is connected to the heat exchanger of the low pressure side vessel of the other pair of vessels and the heat exchanger of the high pressure side vessel of the one pair of vessels, and heat exchange of the low pressure side vessel of the one pair of vessels. And a heat exchanger of the heat radiating unit, and second switching control means for switching to connect the heat exchanger of the high pressure side container of the other pair of containers and the heat exchanger of the cooling load. Is provided.

[0010]

According to the invention of claim 1, the cold heat generated in the low-pressure side container of the one pair of containers at the first cycle is supplied to the high-pressure side container of the other pair of containers to be cooled, and the other pair of containers is also cooled. While the stored heat generated in the low-pressure side container of the container is radiated, the desired cold heat generated in the high-pressure side container of the pair of one container is taken out. At the time of the second cycle, the cold heat generated in the low pressure side container of the other pair of containers by switching the hydrogen transfer by the compressor from the other pair of containers to the pair of one container causes the cold heat generated in the pair of high pressure side containers of the one pair of containers. While being supplied and cooled inside, the stored heat generated in the low pressure side container of the pair of one container is radiated, while the desired cold heat generated in the high pressure side container of the other pair of container is taken out. . The first cycle and the second cycle are alternately repeated, and desired cold heat is continuously supplied to the cooling load. As a result, the cold heat of the low-pressure side container that releases hydrogen cools the storage heat of the high-pressure side container that stores hydrogen. it can. Therefore, since the operating pressure on the suction side of the compressor can be made relatively high when cold heat is generated, the compression ratio of the compressor can be made small, and operation can be performed without rotating at high speed. Further, when the low-temperature cold heat of −50 ° C. is taken out, the hydrogen equilibrium pressure at the time of freezing can be kept relatively high. It is possible to take out cold heat at a low temperature of -50 ° C.

According to a second aspect of the present invention, the first switching control means switches the first switching valve to forcibly transfer hydrogen from one pair of vessels to the other pair of vessels by one compressor. 1 cycle and second forcibly transferring hydrogen from the other pair of vessels to the one pair of vessels by the compressor
The cycle is repeated alternately. In the second switching control means, by switching the second switching valve, during the first cycle, the heat exchanger for the low-pressure side container of the pair of one container and the heat exchanger for the high-pressure side container of the other pair of containers are used. Connect
The heat exchanger of the low-pressure side container of the other pair of containers and the heat exchanger of the heat dissipation part are connected, and the heat exchanger of the high-pressure side container of the pair of containers and the heat exchanger of the cooling load are respectively connected. In the second cycle, the heat exchanger of the low-pressure side container of the other pair of containers and the heat exchanger of the high-pressure side container of the pair of one container are connected to each other, and the low-pressure side container of the pair of one container is connected. And the heat exchanger of the heat radiating portion are connected, and the heat exchanger of the high pressure side container of the other pair of containers and the heat exchanger of the cooling load are connected. As a result, the cold heat of the low-pressure side container that releases hydrogen cools the storage heat of the high-pressure side container that stores hydrogen. it can. Therefore, since the operating pressure on the suction side of the compressor can be made relatively high when cold heat is generated, the compression ratio of the compressor can be made small, and operation can be performed without rotating at high speed. Further, when the low-temperature cold heat of -50 ° C. is taken out, the hydrogen equilibrium pressure during freezing can be kept relatively high, so that the pressurization can be sufficiently performed without rotating the compressor at a high speed, and the continuous pressure can be continuously applied. It is possible to take out cold heat at a low temperature of -50 ° C. Further, it can be carried out by one compressor without using two compressors for forced transfer of hydrogen.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a cold heat generator showing an embodiment of the present invention. In the figure, storage containers 1 and 2
The heat exchangers 1a and 2a are hermetically built in, and the hydrogen absorbing / releasing pipes 1b and 2b with a filter are attached, and in the operating temperature range of this system, a LaNi ₅ system metal having a low hydrogen equilibrium pressure is used. Each of them is filled with hydride MH2.

Further, the storage containers 3 and 4 respectively have the heat exchangers 3a and 4a airtightly incorporated therein, and the hydrogen absorbing / releasing pipes 3b and 4b with the filter are attached, and in the operating temperature range of this system, Mm (Misch metal) Ni ₅ -based metal hydrides MH1 having a high hydrogen equilibrium pressure are filled.

In the compressor 5, a discharge side pipe 6a and a suction side pipe 6b are connected, and check valves 7a, 7 are connected to these.
b, 7c, 7d are connected so as to flow only in one direction, one hydrogen conduit 8a is connected to the hydrogen storage / release pipe 1b of the storage container 1 via the electric valve 9a, and the storage container 3
Is connected to the hydrogen storage / release pipe 3b of the storage container 4, and the other hydrogen conduit 8b is connected to the hydrogen storage / release pipe 2b of the storage container 2 via the electric valve 9b.
connected to b.

The heat radiating section 10 has a built-in air-cooled or water-cooled heat exchanger 10a, and a heat-medium transport pipe 11 using water, alcohol or the like as a heat medium is a three-way valve 12a-12 of the heat medium switching section 12.
By d, it is connected to the heat exchanger 1a of the storage container 1 in the first cycle described later, and is connected to the heat exchanger 2a of the storage container 2 in the second cycle. Cooling load 13
Is a freezer provided with a fan and the like, and includes a heat exchanger 13a.
And a heat medium transport pipe 14 having water, alcohol or the like as a heat medium is connected to the heat exchanger 3a of the storage container 3 in the first cycle by the three-way valves 12e to 12h of the heat medium switching unit 12, while the second The heat exchanger 4a of the storage container 4 is connected in a cycle.

Further, in the heat medium switching section 12, the three-way valve 12a
~ 12h through the heat medium transport pipe 15 in the first cycle heat exchanger 2a of the storage container 2 and the heat exchanger 3 of the storage container 3
While a is connected to a, the heat exchanger 1a of the storage container 1 and the heat exchanger 4a of the storage container 4 are connected in the second cycle.

The control unit 16 outputs a control signal for the first cycle and a control signal for the second cycle to the heat medium switching unit 12 to output the three-way valve 12a.
.About.12h are switched, the electric valves 9a and 9b are controlled, and the compressor 5 is further controlled.

With the above configuration, first, in the control section 16, the control signal of the first cycle is output to the heat medium switching section 12 in the first cycle of the cooling operation. Thereby, based on the control signal of the first cycle, as shown in the connection relationship of FIG. 2, the heat exchanger 1a of the storage container 1 and the heat exchanger of the heat radiating unit 10 are controlled by the three-way valves 12a to 12h of the heat medium switching unit 12. 10a
And the heat exchanger 4a of the storage container 4 and the heat exchanger 13a of the cooling load 13 are connected via the heat medium transport pipe 14, and the storage container 2 The heat exchanger 2 a and the heat exchanger 3 a of the storage container 3 are connected via the heat medium transport pipe 15.

Then, the heat exchanger 10a of the heat radiating section 10 is cooled by air cooling or water cooling, and a cooled heat medium such as water or alcohol flows into the heat exchanger 1a of the storage container 1 so that the inside of the storage container 1 is at room temperature ( The temperature is maintained at about 20 ° C.

In this state, the inside of the storage container 1 is at room temperature and the metal hydride MH2 is in the state A as shown in FIG. 4, which is stored in comparison with the pressure applied to the discharge side pipe 6a of the compressor 5. The pressure on the container 1 side is slightly low. On the other hand, the storage container 2
The metal hydride MH2 is in the state B as shown in FIG. 4, and the pressure on the storage container 2 side is slightly higher than the suction pressure of the suction side pipe 6b of the compressor 5.

Here, the compressor 5 is driven by a signal from the control unit 16, and the motor-operated valve 9a,
When the opening operation of 9b is performed, the storage container 2 has a slightly higher pressure than the suction pressure of the compressor 5, and the storage container 1 has a slightly lower pressure with respect to the pressurization of the compressor 5, so the check valve 7d. Hydrogen that has been sucked in through the compressor 5 and has been pressurized from the compressor 5 flows into the storage container 1 through the check valve 7a, the hydrogen conduit 8a and the motor-operated valve 9a, and is exothermically stored in the metal hydride MH2.

At this time, the heat generated in the storage container 1 is
The heat medium is exchanged with the heat medium by the heat exchanger 1a, and the heat medium transport pipe 11
The heat is radiated from the heat radiating section 10.

At the same time, in the storage container 2, hydrogen is sucked by the compressor 5 to dissociate the hydrogen from the metal hydride MH2, and the hydrogen is sucked into the compressor 5 through the electric valve 9b and the hydrogen conduit 8b. At this time, cold heat of about −20 ° C. is generated in the storage container 2 due to hydrogen dissociation of the metal hydride MH2, and accordingly, the heat medium is cooled by the heat exchanger 2a and connected to the heat medium transport pipe 15. The inside of the storage container 3 is cooled via the heat exchanger 3a of the storage container 3, and the pressure is gradually reduced.

When the pressure in the storage container 3 becomes low, the hydrogen pressurized from the compressor 5 passes through the hydrogen pipe 8a and the motor-operated valve 9a via the check valve 7a and flows into the storage container 3 to generate a large amount of hydrogen. It is occluded by the metal hydride MH1 and enters the state of C shown in FIG.

At this time, hydrogen is released by the suction of the compressor 5 through the motor-operated valve 9b, the hydrogen conduit 8b and the check valve 7d, the metal hydride MH1 in the storage container 4 dissociates the hydrogen, and D shown in FIG. Like the state of about -50 ℃
A level of cold heat is generated, and the heat medium transport pipe 1 is fed from the heat exchanger 4a.
It is supplied to the cooling load 13 via 4.

Immediately after the completion of this first cycle, as shown in FIG. 4, the inside of the storage container 2 is at room temperature and the metal hydride MH2 is in the A state, and the discharge side pipe 6a of the compressor 5 is in a state. The pressure on the side of the storage container 2 is slightly lower than the pressurizing pressure. On the other hand, the metal hydride MH2 of the storage container 1
4 is in the state B as shown in FIG. 4, and the pressure on the storage container 1 side is slightly higher than the suction pressure of the suction side pipe 6b of the compressor 5. Further, the metal hydride MH1 of the storage container 4 is in the state D shown in FIG. 4, and the metal hydride MH1 of the storage container 3 is in the state C shown in FIG. At this time, the control signal of the second cycle is output from the control unit 16 to the heat medium switching unit 12.

Accordingly, in the heat medium switching unit 12, as shown in FIG. 3, the heat exchanger 1a of the storage container 1 and the heat exchanger 4a of the storage container 4 are connected by the three-way valves 12a to 12h. And the heat exchanger 2a of the storage container 2 and the heat exchanger 10a of the heat radiating portion 10 are connected to each other via the heat medium transport pipe 1
1 through which the heat exchanger 3 of the storage container 3 is connected.
a and the heat exchanger 13a of the cooling load 13 are heat medium transport pipes 14
Connected via.

In the heat radiation section 10, the heat exchanger 10a
Is cooled by air cooling or water cooling, and the cooled heat medium flows to the heat exchanger 2a of the storage container 2, and the inside of the storage container 2 has about 20
It is kept at room temperature of ℃. Therefore, at the beginning of the second cycle, the inside of the storage container 2 is at room temperature, the metal hydride MH2 is in the A state as shown in FIG. 4, and the pressure applied to the discharge side pipe 6a of the compressor 5 is increased. Is higher than the pressure inside the storage container 2. On the other hand, the metal hydride MH2 in the storage container 1 is
In the state B shown in FIG. 4, the pressure on the side of the storage container 1 is higher than that on the suction side pipe 6b of the compressor 5.

In this state, the compressor 5 is driven by the signal from the control unit 16, and the motor-operated valve 9 is driven by the signal from the control unit 16.
When a and 9b are opened, the storage container 1 moves to the compressor 5
Since it is slightly higher than the suction pressure of H.sub.2, the hydrogen sucked through the check valve 7b and pressurized by the compressor 5 receives hydrogen through the check valve 7c and the hydrogen conduit 8b and the motor-operated valve 9.
It flows into the storage container 2 through b, and is exothermically stored in the metal hydride MH2. At this time, the stored heat generated in the storage container 2 is heat-exchanged with the heat medium by the heat exchanger 2a and is radiated from the heat medium transport pipe 11 to the heat radiating unit 10.

At the same time, in the storage container 1, hydrogen is dissociated from the metal hydride MH2, and the hydrogen is sucked into the compressor 5 via the electric valve 9a and the hydrogen conduit 8a. At this time, in the storage container 1, cold heat of about −20 ° C. is generated by hydrogen dissociation of the metal hydride MH2, and the storage container 4 connected by the heat medium transport pipe 15 is cooled to a low pressure.

When the pressure in the storage container 4 becomes low, hydrogen pressurized from the compressor 5 flows into the storage container 4 through the hydrogen valve 8b and the electric valve 9b via the check valve 7c, and a large amount of hydrogen is stored. It is occluded by the metal hydride MH1 in the container 4, enters the state of C shown in FIG. 4, and is used for load cooling in the next first cycle.

In this state, due to the suction of the compressor 5, hydrogen is released through the motor-operated valve 9a, the hydrogen conduit 8a and the check valve 7b, and in the storage container 3, the hydrogen stored in the first cycle is the metal hydrogen. Dissociated from the compound MH1,
Cold heat at a level of −50 ° C. is generated by the endothermic reaction, the state becomes D shown in FIG. 4, and the heat is supplied from the heat exchanger 3 a to the cooling load 13 via the heat medium transport pipe 14.

The first cycle and the second cycle described above are alternately repeated based on the signal from the control unit 16, and the heat exchangers 3a and 4a and the heat medium transport pipe 14 are alternately arranged from the storage container 3 and the storage container 4. Cold heat is continuously supplied to the cooling load 13 via.

As described above, since the operating pressure on the suction side of the compressor can be made relatively high when cold heat is generated, the compression ratio of the compressor can be made small, and the compressor can be operated without rotating at high speed. Further, when the low-temperature cold heat of −50 ° C. is taken out, the hydrogen equilibrium pressure at the time of freezing can be kept relatively high. It is possible to take out cold heat at a low temperature of -50 ° C. Further, it can be carried out by one compressor without using two compressors for forced transfer of hydrogen.

[0036]

As described above, according to the present invention, the flow of hydrogen is switched between the pair of one container and the other pair of containers by the compressor so as to alternately invert the flow of hydrogen, and correspondingly, The heat exchangers of the pair of containers and the other pair of containers are appropriately connected to the respective heat exchangers. Therefore, since the operating pressure at the time of generation of cold heat can be made relatively high, the compression ratio of the compressor can be made small, and sufficient pressurization can be performed without rotating the compressor at a high speed, which facilitates the operation.
Further, low-temperature cold heat of -50 ° C level can be taken out. Moreover, it is possible to generate low-temperature cold heat of -50 ° C. level with one compressor without using two compressors.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a cold heat generator according to an embodiment of the present invention.

2 is an explanatory diagram showing a first cycle of the cold heat generator of FIG. 1. FIG.

FIG. 3 is an explanatory diagram showing a second cycle of the cold heat generator of FIG. 1.

FIG. 4 is an explanatory diagram showing hydrogen gas absorption / desorption characteristics of metal hydride.

[Explanation of symbols]

 1, 2, 3, 4 Storage container 1a, 2a, 3a, 4a, 10a, 13a Heat exchanger 1b, 2b, 3b, 4b Hydrogen absorption / desorption pipe 5 Compressor 6a Discharge side pipe 6b Suction side pipe 7a, 7b, 7c , 7d Check valve 8a, 8b Hydrogen conduit 9a, 9b Motorized valve 10 Heat dissipation part 11, 14, 15 Heat medium transport pipe 12 Heat medium switching part 12a-12h Three-way valve 13 Cooling load 16 Control part

Claims (2)

[Claims] 1. A pair of vessels comprising a heat exchanger and a low pressure side vessel filled with a metal hydride having a low equilibrium hydrogen pressure characteristic, and a high pressure side vessel filled with a heat exchanger and a metal hydride having a high equilibrium hydrogen pressure characteristic. Are connected to each other via hydrogen compressors through two sets of compressors, and the one pair of containers is forcibly transferred by the compressor from one pair of containers of the two sets to the other pair of containers. The cold heat generated in the low-pressure side container of the container is supplied through the heat exchanger into the high-pressure side container of the other pair of containers to be cooled, and the other pair of While radiating the occlusion heat generated in the low pressure side container of the container, the first cycle of extracting the desired cold heat generated in the high pressure side container of the one pair of containers via the heat exchanger, and the other of the One of the one from the pair of containers The cold heat generated in the low pressure side container of the other pair of containers by switching the hydrogen transfer by the compressor to the pair of containers via the heat exchanger into the high pressure side container of the one pair of containers While supplying and cooling through a heat exchanger, while radiating the occlusion heat generated in the low pressure side container of the one pair of containers, the desired generated in the high pressure side container of the other pair of containers A method for generating cold heat, characterized in that the desired cold heat is continuously supplied to a cooling load by alternately repeating a second cycle in which cold heat is taken out through the heat exchanger. 2. A pair of a low pressure side container filled with a metal hydride having a low equilibrium hydrogen pressure characteristic together with a heat exchanger, and a high pressure side container filled with a metal hydride having a high equilibrium hydrogen pressure characteristic together with a heat exchanger. The other pair of the low pressure side container filled with the metal hydride having a low equilibrium hydrogen pressure characteristic together with the heat exchanger and the high pressure side container filled with the metal hydride having a high equilibrium hydrogen pressure characteristic together with the heat exchanger. Container and
A hydrogen conduit provided by connecting the one pair of containers and the other pair of containers, a first switching valve provided in the hydrogen conduit for switching the transfer of hydrogen, and forcibly transferring hydrogen One compressor, a heat radiating section having a heat exchanger for radiating heat, a cooling load having a heat exchanger, a heat medium pipe for appropriately switching and connecting between the heat exchangers, and a heat medium thereof. A first switching valve provided on a pipe and the first switching valve are switched to forcibly transfer hydrogen from the one pair of vessels to the other pair of vessels by the compressor. First switching control means alternately repeating a cycle and a second cycle in which hydrogen is forcibly transferred from the other pair of vessels to the one pair of vessels by the compressor; and the second switching valve. By switching the first cycle Sometimes, the heat exchanger of the low pressure side container of the one pair of vessels and the heat exchanger of the high pressure side vessel of the other pair of containers are connected, and the heat exchanger of the low pressure side vessel of the other pair of containers And the heat exchanger of the heat dissipation part are connected,
Switching to connect the heat exchanger of the high-pressure side container of the one pair of containers and the heat exchanger of the cooling load, respectively,
At the time of the second cycle, the heat exchanger of the low pressure side container of the other pair of containers and the heat exchanger of the high pressure side container of the one pair of containers are connected to each other, and the low pressure side container of the one pair of containers is connected. The second heat exchanger and the heat exchanger of the heat radiating unit are connected, and the heat exchanger of the high pressure side container of the other pair of containers and the heat exchanger of the cooling load are switched to be connected to each other. A cold heat generator comprising: a control means.