Refrigeration device

Abstract

Refrigeration devices that comprise an adsorption refrigeration cycle have a period in which heat of adsorption or heat of desorption is not recovered, immediately after the switching of a refrigerant flow path, and have a risk of decline in performance. A refrigeration device (100) comprises a refrigerant flow path (111), a compressor (131), a first adsorber (121), a second adsorber (122), a switching mechanism (135), a first pressure vessel (171), a second pressure vessel (172), an opening / closing mechanism, and a control unit (105). The first adsorber (121) and the second adsorber (122) have an adsorbent (181). The control unit (105) executes: first control for allowing a flow of a refrigerant between the first adsorber and the first pressure vessel and the flow of the refrigerant between the second adsorber and the second pressure vessel; second control for switching the refrigerant flow path between a first state and a second state; third control for allowing the flow of the refrigerant between the first adsorber and the second adsorber; and fourth control for allowing the flow of the refrigerant between the first adsorber and the second pressure vessel and the flow of the refrigerant between the second adsorber and the first pressure vessel.

Description

Refrigeration equipment

[0001] Regarding refrigeration equipment.

[0002] Conventionally, refrigeration systems equipped with an adsorption refrigeration cycle have been used. Patent Document 1 (U.S. Patent Application Publication No. 2023 / 0417459) discloses such a refrigeration system including a heat source circuit having a pair of adsorbers that alternately adsorb and desorb a refrigerant, and a user circuit through which a heat medium circulates to recover the heat of adsorption or desorption of the refrigerant. The heat source circuit alternates between a mode in which the refrigerant is adsorbed by one adsorber and desorbed by the other adsorber, and a mode in which the refrigerant is desorbed by the one adsorber and adsorbed by the other adsorber. As a result, the user circuit continuously recovers heat from the heat source circuit using the heat medium.

[0003] After the mode is switched in the heat source circuit, the internal pressure of the adsorber needs to increase or decrease to a predetermined value until the adsorber starts to adsorb or desorb the refrigerant. If it takes a long time for the internal pressure of the adsorber to increase or decrease, the period during which the heat medium does not recover heat or cold will become longer, which may reduce the capacity of the refrigeration system.

[0004] A refrigeration apparatus according to a first aspect includes a refrigerant flow path through which a refrigerant flows, a compressor, a first adsorbent, a second adsorbent, a switching mechanism, a first pressure vessel, a second pressure vessel, an opening / closing mechanism, and a control unit. The compressor draws in and compresses a low-pressure refrigerant, and discharges it as a high-pressure refrigerant. The first and second adsorbents have adsorbents that adsorb and desorb the refrigerant in response to changes in the refrigerant pressure. The first and second adsorbents recover heat generated when the adsorbent adsorbs the refrigerant, and cold generated when the adsorbent desorbs the refrigerant. The first pressure vessel is connected to the discharge side of the compressor. The second pressure vessel is connected to the suction side of the compressor. The opening / closing mechanism is provided on the refrigerant flow path and allows or blocks the flow of refrigerant between the first adsorbent, the second adsorbent, the first pressure vessel, and the second pressure vessel. The control unit controls the switching mechanism and the opening / closing mechanism. The switching mechanism is capable of switching the refrigerant flow path between a first state and a second state. In the first state, the first pressure vessel and the first adsorber can be connected to create a high-pressure state in the first adsorber, and the second pressure vessel and the second adsorber can be connected to create a low-pressure state in the second adsorber. In the second state, the second pressure vessel and the first adsorber can be connected to create a low-pressure state in the first adsorber, and the first pressure vessel and the second adsorber can be connected to create a high-pressure state in the second adsorber. The control unit executes first control, second control, third control, and fourth control. The first control controls the opening and closing mechanism to allow refrigerant to flow between the first adsorber and the first pressure vessel, and to allow refrigerant to flow between the second adsorber and the second pressure vessel. The second control controls the switching mechanism to switch the refrigerant flow path between the first state and the second state. The third control allows the refrigerant to flow between the first adsorber and the second adsorber to reduce the difference in refrigerant pressure between the first adsorber and the second adsorber. The fourth control controls the opening and closing mechanism to allow the refrigerant to flow between the first adsorber and the second pressure vessel and to allow the refrigerant to flow between the second adsorber and the first pressure vessel.

[0005] In the refrigeration apparatus of the first aspect, when the refrigerant flow path is switched, the first pressure vessel and the first adsorber are connected, causing the first adsorber to be in a high-pressure state, and the second pressure vessel and the second adsorber are connected, causing the second adsorber to be in a low-pressure state. This shortens the time from when the refrigerant flow path is switched until the pressure inside the adsorber reaches the adsorption pressure or desorption pressure, thereby shortening the period during which hot or cold energy cannot be recovered from the adsorber, thereby suppressing a decrease in the capacity of the refrigeration apparatus.

[0006] A refrigeration apparatus according to a second aspect is the refrigeration apparatus according to the first aspect, wherein the opening and closing mechanism includes a first valve and a second valve. The first valve is provided in the refrigerant flow path between the first pressure vessel and the first adsorber when the refrigerant flow path is in the first state. The second valve is provided in the refrigerant flow path between the second pressure vessel and the second adsorber when the refrigerant flow path is in the first state.

[0007] A refrigeration apparatus according to a third aspect is the refrigeration apparatus according to the second aspect, wherein the control unit executes the first control by opening the first valve and the second valve when the refrigerant flow path is in the first state.

[0008] A refrigeration device of a fourth aspect is the refrigeration device of the second or third aspect, in which the control unit performs the second control by closing the first valve and the second valve and controlling the switching mechanism to switch between the first state and the second state.

[0009] A refrigeration device of a fifth aspect is a refrigeration device of any one of the second to fourth aspects, in which the control unit performs the fourth control by opening the first valve and the second valve when the refrigerant flow path is in the second state.

[0010] A refrigeration apparatus according to a sixth aspect is the refrigeration apparatus according to any one of the first to fifth aspects, further including a bypass flow path and a bypass valve. The bypass flow path connects the first adsorption device and the second adsorption device without passing through the compressor. The bypass valve is provided in the bypass flow path. The control unit executes the third control by opening the bypass valve to reduce a difference between the pressure of the refrigerant in the first adsorption device and the pressure of the refrigerant in the second adsorption device, and then closing the bypass valve.

[0011] A refrigeration device of a seventh aspect is the refrigeration device of any one of the first to sixth aspects, in which the control unit performs the first control, then performs the second control and the third control, and then performs the fourth control.

[0012] A refrigeration device according to an eighth aspect is the refrigeration device according to the seventh aspect, wherein the control unit executes the second control and the third control so that a period during which the second control is executed and a period during which the third control is executed overlap.

[0013] A ninth aspect of the refrigeration device is the refrigeration device of the seventh aspect, wherein the control unit repeats a cycle of performing the first control, the second control, the third control, the fourth control, the second control, the third control, and the first control in this order.

[0014] A refrigeration device of a tenth aspect is a refrigeration device of any one of the first to ninth aspects, wherein the control unit further performs a fifth control, which controls the compressor so that the internal pressure of the first pressure vessel is within a predetermined range when at least one of the first to fourth controls is performed.

[0015] A refrigeration apparatus according to an eleventh aspect is the refrigeration apparatus according to the tenth aspect, wherein the control unit executes the fifth control by controlling the rotation speed of the compressor without stopping the compressor.

[0016] A refrigeration device of a twelfth aspect is a refrigeration device of the tenth or eleventh aspect, in which the control unit executes the fifth control by controlling at least one of the timing of starting the compressor and the timing of stopping the compressor.

[0017] A refrigeration device according to a thirteenth aspect is the refrigeration device according to any one of the first to twelfth aspects, wherein the adsorbent includes a metal-organic framework including metal ions and organic ligands.

[0018] A refrigeration apparatus according to a fourteenth aspect is the refrigeration apparatus according to any one of the first to thirteenth aspects, wherein the refrigerant flowing through the refrigerant flow passage is selected from the group consisting of carbon dioxide, hydrocarbon refrigerant, ammonia, and water.

[0019] FIG. 1 is a schematic diagram of a refrigeration device 100 of a first embodiment. FIG. 2 is a block diagram of the refrigeration device 100 of the first embodiment. FIG. 3 is a schematic diagram of a first adsorption device 121 and a second adsorption device 122 of the first embodiment. FIG. 4 is a time chart of the pressure and heat quantity of the first adsorption device 121 as a comparative example. FIG. 5 is a time chart of the pressure and heat quantity of the first adsorption device 121 of the first embodiment. FIG. 6 is a schematic diagram of a refrigeration device 100 of a second embodiment. FIG. 7 is a schematic diagram of a refrigeration device 100 of a third embodiment. FIG. 8 is a schematic diagram of a refrigeration device 100 of a fourth embodiment. FIG. 9 is a block diagram of a refrigeration device 100 of the fourth embodiment. FIG. 10 is a flowchart of control of the refrigeration device 100 of the fourth embodiment. FIG. 11 is a time chart of control of the refrigeration device 100 of the fourth embodiment. FIG. 12 is a schematic diagram of a refrigeration device 100 of a modification A. FIG. 13 is a schematic diagram of a refrigeration device 100 of a modification E. FIG. 14 is a time chart of control of the refrigeration device 100 of a modification H. FIG. 15 is a time chart of control of the refrigeration device 100 of a modification H.

[0020] First Embodiment (1) Overall Configuration of Refrigeration Device 100 As shown in FIG. 1 , the refrigeration device 100 of the first embodiment includes a heat source side circuit 101 and a utilization side circuit 102. The heat source side circuit 101 has a refrigerant flow path 111 through which a refrigerant flows. The utilization side circuit 102 has a heat medium flow path 112 through which a heat medium flows. In FIG. 1 , the refrigerant flow path 111 is depicted by a thick line. The refrigerant flowing through the refrigerant flow path 111 is selected from the group consisting of, for example, carbon dioxide, hydrocarbon refrigerant, ammonia, and water. The hydrocarbon refrigerant is selected from the group consisting of, for example, propane, butane, and isobutane. The heat medium flowing through the heat medium flow path 112 is selected from the group consisting of, for example, water, brine, and air. Brine is a liquid with a freezing point of 0° C. or lower. The refrigeration device 100 is, for example, an air conditioning device.

[0021] The refrigeration apparatus 100 further includes a control unit 105. As shown in FIG. 2 , the control unit 105 controls the operation of each element constituting the heat source side circuit 101 and the utilization side circuit 102. Here, a processor is illustrated as an example of the control unit 105. The processor is made up of various computing devices such as a central processing unit (CPU), a digital signal processor (DSP), a field-programmable gate array (FPGA), and a graphics processing unit (GPU). The processor reads various programs of the apparatus into memory and executes them. The processor loads programs stored in memory into a working area of ​​the memory, executes them, and realizes functions that meet a predetermined purpose by controlling each component through the execution of the programs.

[0022] (1-1) Heat Source Side Circuit 101 The heat source side circuit 101 constitutes a refrigeration cycle that functions as a heat pump that utilizes heat (hot heat or cold heat) generated when the refrigerant is adsorbed to or desorbed from the adsorbent.

[0023] The heat source side circuit 101 has a compressor 131, a first adsorption device 121, a second adsorption device 122, a switching mechanism 135, a first pressure vessel 171, and a second pressure vessel 172. The refrigerant flow path 111 connects the compressor 131, the first adsorption device 121, the second adsorption device 122, the switching mechanism 135, the first pressure vessel 171, and the second pressure vessel 172.

[0024] The compressor 131 compresses the refrigerant flowing through the refrigerant flow path 111. The compressor 131 is, for example, a rotary compressor. The compressor 131 draws in low-pressure refrigerant from the refrigerant flow path 111, compresses it, and discharges it into the refrigerant flow path 111 as high-pressure refrigerant. The low-pressure refrigerant is the refrigerant in the refrigerant flow path 111 before being compressed by the compressor 131. The high-pressure refrigerant is the refrigerant in the refrigerant flow path 111 after being compressed by the compressor 131. During operation of the compressor 131, lubricating oil sealed in the refrigerant flow path 111 is supplied to the sliding parts of the compressor 131. A portion of the lubricating oil is accumulated at the bottom of the casing of the compressor 131.

[0025] The first adsorption device 121 and the second adsorption device 122 have an adsorbent that adsorbs and desorbs the refrigerant. In the first adsorption device 121 and the second adsorption device 122, the heat of adsorption or desorption heat is recovered by the heat medium flowing through the heat medium flow path 112. The heat of adsorption is hot heat generated when the adsorbent adsorbs the refrigerant. The heat of desorption is cold heat generated when the adsorbent desorbs the refrigerant. The generation of hot heat refers to an increase in the temperature of the heat medium due to the heat medium absorbing heat. The generation of cold heat refers to a decrease in the temperature of the heat medium due to the heat absorption from the heat medium. The first adsorption device 121 and the second adsorption device 122 are connected to the switching mechanism 135 in the refrigerant flow path 111.

[0026] The switching mechanism 135 switches the flow direction of the refrigerant flowing through the refrigerant flow path 111. The switching mechanism 135 is, for example, a four-way switching valve. The switching mechanism 135 is configured to be able to switch the refrigerant flow path 111 between a first state in which the flow direction is indicated by the solid line in FIG. 1 and a second state in which the flow direction is indicated by the dashed line in FIG. 1. In the first state, the discharge side of the compressor 131 is connected to the first adsorption device 121, and the suction side of the compressor 131 is connected to the second adsorption device 122. In the second state, the discharge side of the compressor 131 is connected to the second adsorption device 122, and the suction side of the compressor 131 is connected to the first adsorption device 121.

[0027] The first pressure vessel 171 is connected to the discharge side of the compressor 131. The first pressure vessel 171 is provided in the refrigerant flow path 111 between the discharge side of the compressor 131 and the switching mechanism 135.

[0028] The second pressure vessel 172 is connected to the suction side of the compressor 131. The second pressure vessel 172 is provided in the refrigerant flow path 111 between the suction side of the compressor 131 and the switching mechanism 135.

[0029] The control unit 105 controls the compressor 131 and the switching mechanism 135. The control unit 105 controls the rotation speed of the compressor 131. The control unit 105 controls the timing to start the compressor 131 and the timing to stop the compressor 131. The control unit 105 controls the switching mechanism 135 to switch the refrigerant flow path 111 between a first state and a second state.

[0030] The control unit 105 controls the switching mechanism 135 so that the period during which the refrigerant flow path 111 is in the first state and the period during which the refrigerant flow path 111 is in the second state are the same length. However, the control unit 105 may also control the switching mechanism 135 so that the period during which the refrigerant flow path 111 is in the first state and the period during which the refrigerant flow path 111 is in the second state are different lengths. The period during which the refrigerant flow path 111 is in the first state is the period from the time when the refrigerant flow path 111 switches to the first state to the time when it switches to the second state. The period during which the refrigerant flow path 111 is in the second state is the period from the time when the refrigerant flow path 111 switches to the second state to the time when it switches to the first state.

[0031] (1-2) Use-Side Circuit 102 The use-side circuit 102 functions as a heat transfer means for utilizing, via a heat medium, the heat generated in the heat source-side circuit 101. The heat medium flowing through the heat medium flow path 112 transfers the adsorption heat or desorption heat recovered in the first adsorption device 121 or the second adsorption device 122 to a predetermined location.

[0032] The utilization side circuit 102 includes a first fluid pump 141, a first heat exchanger 142, a first fan 143, a first adsorption device 121, a second fluid pump 151, a second heat exchanger 152, a second fan 153, a second adsorption device 122, and flow path changing units 156-159. The heat medium flow path 112 connects the first fluid pump 141, the first heat exchanger 142, the first adsorption device 121, the second fluid pump 151, the second heat exchanger 152, the second adsorption device 122, and the flow path changing units 156-159.

[0033] The first fluid pump 141 sends the heat medium to the first heat exchanger 142. The first heat exchanger 142 exchanges heat between the heat medium and air. The first fan 143 generates a flow of air passing through the first heat exchanger 142 so that heat exchange occurs in the first heat exchanger 142.

[0034] The second fluid pump 151 sends the heat medium to the second heat exchanger 152. The second heat exchanger 152 exchanges heat between the heat medium and air. The second fan 153 generates a flow of air passing through the second heat exchanger 152 so that heat exchange occurs in the second heat exchanger 152.

[0035] The flow path changing units 156-159 change the flow path through which the heat medium flows by switching the connection state of the heat medium flow path 112. The flow path changing units 156-159 are, for example, three-way switching valves. The flow path changing units 156-159 are configured to be able to switch the heat medium flow path 112 between a third connection state shown by the solid line in Fig. 1 and a fourth connection state shown by the dashed line in Fig. 1.

[0036] The heat medium flow path 112 has two independent flow paths, a first circulation path and a second circulation path, in each of the third state and the fourth state. The heat medium circulates through each of the first circulation path and the second circulation path. In Fig. 1 , the flow direction of the heat medium in the third state is indicated by a solid line, and the flow direction of the heat medium in the fourth state is indicated by a dashed line.

[0037] In the third state, the first circulation flow path connects the first fluid pump 141, the first heat exchanger 142, the flow path changing unit 156, the first adsorption device 121, and the flow path changing unit 157. In the third state, the second circulation flow path connects the second fluid pump 151, the second heat exchanger 152, the flow path changing unit 158, the second adsorption device 122, and the flow path changing unit 159.

[0038] In the fourth state, the first circulation flow path connects the first fluid pump 141, the first heat exchanger 142, the flow path changing unit 156, the second adsorption device 122, and the flow path changing unit 157. In the fourth state, the second circulation flow path connects the second fluid pump 151, the second heat exchanger 152, the flow path changing unit 158, the first adsorption device 121, and the flow path changing unit 159.

[0039] The control unit 105 controls the first fluid pump 141, the first fan 143, the second fluid pump 151, the second fan 153, and the flow path changing units 156-159. The control unit 105 controls the capacity of the first fluid pump 141 and the second fluid pump 151. The control unit 105 controls the rotation speed of the first fan 143 and the second fan 153. The control unit 105 controls the flow path changing units 156-159 to switch the heat medium flow path 112 between the third state and the fourth state.

[0040] (1-3) First Adsorption Device 121 and Second Adsorption Device 122 The first adsorption device 121 and the second adsorption device 122 each include a heat recovery member, an adsorption material, and a casing. The first adsorption device 121 and the second adsorption device 122 each have a first space through which the refrigerant flows and a second space through which the heat medium flows. The first space is part of the refrigerant flow path 111. The second space is part of the heat medium flow path 112. The first space and the second space do not communicate with each other.

[0041] The heat recovery member separates the first space from the second space. The adsorbent is provided in the first space. The adsorbent adsorbs and desorbs the refrigerant in the first space in response to changes in the pressure of the refrigerant in the first space. The adsorbent is supported on a first surface, which is a surface of the heat recovery member.

[0042] The adsorbent supported on the first surface includes a metal-organic framework (MOF) containing metal ions and organic ligands. The metal-organic framework is a porous material having an extremely large specific surface area obtained by the reaction of metal ions with organic ligands. In the metal-organic framework, the organic ligands are linked to the metal ions to obtain a polymer structure having countless openings therein. The metal-organic framework can adjust the opening size and topology by selecting and combining the metal ions and organic ligands. Therefore, the metal-organic framework can adjust the opening size and selectively adsorb a target substance by selecting and combining the metal ions and organic ligands. The metal-organic framework can be used, for example, as a porous material having the function of selectively storing and separating molecules and ions.

[0043] In the refrigeration device 100, the metal-organic framework is used as an adsorbent for adsorbing and desorbing the refrigerant flowing through the refrigerant flow path 111. Examples of metal-organic frameworks include MOF-5, MOF-200, UiO-66, and MIL-101. The adsorbent used in the refrigeration device 100 is, for example, a powder of a metal-organic framework or a molded product of a metal-organic framework. In this case, the adsorbent is supported on the first surface by adhering a mixture of the adsorbent and a binder to the first surface. Examples of the binder include an acrylic resin, a polyester resin, a polyolefin resin, and a polyurethane resin.

[0044] The heat recovery member is a cross-fin type. As shown in FIG. 3 , the heat recovery member includes a plurality of fins 161 and heat transfer tubes 162. The heat transfer tubes 162 have a plurality of straight tube sections 162a extending linearly and a folded section 162b connecting two straight tube sections 162a. In FIG. 3 , the thickness of the heat transfer tubes 162 is omitted. The plurality of fins 161 have through holes in their thickness direction through which the straight tube sections 162a of the heat transfer tubes 162 pass. The plurality of fins 161 are stacked around the straight tube sections 162a of the heat transfer tubes 162 at predetermined intervals along the direction in which the straight tube sections 162a extend. A first end 162c and a second end 162d of the heat transfer tubes 162 are connected to the heat medium flow path 112. The plurality of fins 161 and the heat transfer tubes 162 are housed in a casing 163. The casing 163 has an inlet 163 a connected to the refrigerant flow path 111 .

[0045] The refrigerant flowing through the refrigerant flow path 111 flows into the casing 163 through the inlet 163a and flows out of the casing 163 through the inlet 163a. ​​The heat medium flowing through the heat medium flow path 112 flows into the heat transfer tube 162 through the first end 162c and flows out of the heat transfer tube 162 through the second end 162d.

[0046] As shown in FIG. 3 , the first space 164a through which the refrigerant flows is a space inside the casing 163 and outside the heat transfer tube 162. The second space 164b through which the heat medium flows is a space inside the casing 163 and inside the heat transfer tube 162. The first surface 182, on which the adsorbent 181 that adsorbs and desorbs the refrigerant is supported, includes at least a portion of the outer surfaces of the multiple fins 161 and the heat transfer tube 162. The first surface 182 is, for example, the surfaces of the multiple fins 161 and the outer surface of the heat transfer tube 162. The first surface 182 is in contact with the first space 164a. Therefore, the refrigerant in the first space 164a comes into contact with the adsorbent 181 supported on the first surface 182.

[0047] The adsorbent 181 adsorbs the refrigerant in the first space 164a when the pressure of the refrigerant in the first space 164a is equal to or higher than the adsorption pressure. The adsorbent 181 desorbs the refrigerant in the first space 164a when the pressure of the refrigerant in the first space 164a is equal to or lower than the desorption pressure. The adsorption pressure is the minimum value of the range of pressures at which the adsorbent 181 can adsorb the refrigerant at the temperature of the first space 164a. The desorption pressure is the maximum value of the range of pressures at which the adsorbent 181 can desorb the refrigerant at the temperature of the first space 164a. The adsorption pressure and desorption pressure vary depending on the adsorbent 181 and the type of refrigerant.

[0048] (1-4) First Pressure Vessel 171 and Second Pressure Vessel 172 The first pressure vessel 171 and the second pressure vessel 172 are vessels having an inlet and an outlet for the refrigerant. During operation of the refrigeration device 100, the first pressure vessel 171 and the second pressure vessel 172 contain a refrigerant flowing through the refrigerant flow path 111. During operation of the refrigeration device 100, the first pressure vessel 171 contains a high-pressure refrigerant. During operation of the refrigeration device 100, the second pressure vessel 172 contains a low-pressure refrigerant.

[0049] (2) Operation of the Refrigeration Apparatus 100 The operation of the refrigeration apparatus 100 will be described assuming that the refrigeration apparatus 100 is an air conditioning apparatus. In this case, the first heat exchanger 142 is an indoor heat exchanger, and the second heat exchanger 152 is an outdoor heat exchanger.

[0050] The adsorbent 181 of the first adsorption device 121 and the second adsorption device 122 adsorbs and desorbs the refrigerant in the refrigerant flow path 111. The adsorbent 181 adsorbs the refrigerant when it is in contact with a refrigerant whose pressure is equal to or higher than the adsorption pressure in the first space 164a. The adsorbent 181 desorbs the refrigerant when it is in contact with a refrigerant whose pressure is equal to or lower than the desorption pressure in the first space 164a.

[0051] When the refrigerant flow path 111 is in the first state, the first pressure vessel 171 and the first adsorber 121 can be connected to create a high-pressure state inside the first adsorber 121, and the second pressure vessel 172 and the second adsorber 122 can be connected to create a low-pressure state inside the second adsorber 122. When the first adsorber 121 is in a high-pressure state, the adsorbent 181 of the first adsorber 121 is in contact with a high-pressure refrigerant in the first space 164a. When the second adsorber 122 is in a low-pressure state, the adsorbent 181 of the second adsorber 122 is in contact with a low-pressure refrigerant in the first space 164a.

[0052] When the refrigerant flow path 111 is in the second state, it is possible to connect the second pressure vessel 172 and the first adsorption device 121 to create a low-pressure state inside the first adsorption device 121, and to connect the first pressure vessel 171 and the second adsorption device 122 to create a high-pressure state inside the second adsorption device 122. When the first adsorption device 121 is in a low-pressure state, the adsorbent 181 of the first adsorption device 121 is in contact with the low-pressure refrigerant in the first space 164a. When the second adsorption device 122 is in a high-pressure state, the adsorbent 181 of the second adsorption device 122 is in contact with the high-pressure refrigerant in the first space 164a.

[0053] The following describes changes in the adsorption amount, which is the amount of refrigerant adsorbed by the adsorbent 181, when the refrigerant flow path 111 is in the first state. When the switching mechanism 135 switches from the second state to the first state, the adsorption amount of the adsorbent 181 in the first adsorption device 121 is the first adsorption amount, and the adsorption amount of the adsorbent 181 in the second adsorption device 122 is the second adsorption amount. The second adsorption amount is larger than the first adsorption amount. The second adsorption amount is the maximum amount of refrigerant that can be adsorbed by the adsorbent 181. The second adsorption amount includes not only the theoretical maximum amount but also an amount that can change depending on the time the high-pressure pressure or high-pressure state is maintained. The pressure of the high-pressure refrigerant is equal to or greater than the adsorption pressure, and the pressure of the low-pressure refrigerant is equal to or less than the desorption pressure.

[0054] When the refrigerant flow path 111 is in the first state, the adsorbent 181 in the first adsorption device 121 is in contact with a high-pressure refrigerant, and the adsorbent 181 in the second adsorption device 122 is in contact with a low-pressure refrigerant. In the first adsorption device 121, the adsorbent 181 gradually adsorbs the refrigerant, releasing heat in the process. In the second adsorption device 122, the adsorbent 181 gradually desorbs the refrigerant, absorbing heat in the process. Therefore, the adsorption amount of the adsorbent 181 in the first adsorption device 121 increases from the first adsorption amount to the second adsorption amount, and the adsorption amount of the adsorbent 181 in the second adsorption device 122 decreases from the second adsorption amount to the first adsorption amount.

[0055] The following describes a change in the adsorption amount, which is the amount of refrigerant adsorbed by the adsorbent 181, when the refrigerant flow path 111 is in the second state. In the state switched from the first state to the second state by the switching mechanism 135, the adsorption amount of the adsorbent 181 in the first adsorption device 121 is the second adsorption amount, and the adsorption amount of the adsorbent 181 in the second adsorption device 122 is the first adsorption amount.

[0056] When the refrigerant flow path 111 is in the second state, the adsorbent 181 in the first adsorption device 121 contacts the low-pressure refrigerant, and the adsorbent 181 in the second adsorption device 122 contacts the high-pressure refrigerant. In the first adsorption device 121, the adsorbent 181 gradually desorbs the refrigerant, absorbing heat in the process. In the second adsorption device 122, the adsorbent 181 gradually adsorbs the refrigerant, releasing heat in the process. Therefore, the adsorption amount of the adsorbent 181 in the first adsorption device 121 decreases from the second adsorption amount to the first adsorption amount, and the adsorption amount of the adsorbent 181 in the second adsorption device 122 increases from the first adsorption amount to the second adsorption amount.

[0057] When the refrigerant flow path 111 is in the first state and the heat medium flow path 112 is in the third state, in the first adsorption device 121, hot heat generated in the process of the adsorbent 181 adsorbing the refrigerant in the first space 164a is recovered by the heat medium in the second space 164b. On the other hand, in the second adsorption device 122, cold heat generated in the process of the adsorbent 181 desorbing the refrigerant adsorbed by the adsorbent 181 is recovered by the heat medium in the second space 164b. Therefore, in the first adsorption device 121, hot heat is recovered by the heat medium flowing through the first circulation flow path, and in the second adsorption device 122, cold heat is recovered by the heat medium flowing through the second circulation flow path.

[0058] Thereafter, when the adsorption amount of the adsorbent 181 in the first adsorption device 121 reaches the second adsorption amount, it becomes difficult for the adsorbent 181 in the first adsorption device 121 to adsorb the refrigerant. When this state is reached, the refrigerant flow path 111 is switched from the first state to the second state, and the heat medium flow path 112 is switched from the third state to the fourth state.

[0059] When the refrigerant flow path 111 is in the second state and the heat medium flow path 112 is in the fourth state, in the second adsorption device 122, hot heat generated in the process of the adsorbent 181 adsorbing the refrigerant in the first space 164a is recovered by the heat medium in the second space 164b. On the other hand, in the first adsorption device 121, cold heat generated in the process of the adsorbent 181 desorbing the refrigerant adsorbed by the adsorbent 181 is recovered by the heat medium in the second space 164b. Therefore, in the first adsorption device 121, cold heat is recovered by the heat medium flowing through the second circulation flow path, and in the second adsorption device 122, hot heat is recovered by the heat medium flowing through the first circulation flow path.

[0060] Thereafter, when the adsorption amount of the adsorbent 181 in the second adsorption device 122 reaches the second adsorption amount, it becomes difficult for the adsorbent 181 in the second adsorption device 122 to adsorb the refrigerant. When this state is reached, the refrigerant flow path 111 is switched from the second state to the first state, and the heat medium flow path 112 is switched from the fourth state to the third state.

[0061] As described above, by alternately switching the refrigerant flow path 111 between the first state and the second state, it is possible to continuously adsorb or desorb the refrigerant to the adsorbent 181 in either the first adsorber 121 or the second adsorber 122. By alternately switching the heat medium flow path 112 between the third state and the fourth state in accordance with the switching between the first state and the second state, it is possible to continuously recover, by the heat medium flowing through the first circulation flow path, the hot heat generated when the adsorbent 181 adsorbs the refrigerant.

[0062] Furthermore, when the refrigerant flow path 111 is in the first state and the heat medium flow path 112 is in the fourth state, the first adsorption device 121 recovers hot heat to the heat medium flowing through the second circulation path, and the second adsorption device 122 recovers cold heat to the heat medium flowing through the first circulation path. When the refrigerant flow path 111 is in the second state and the heat medium flow path 112 is in the third state, the first adsorption device 121 recovers cold heat to the heat medium flowing through the first circulation path, and the second adsorption device 122 recovers hot heat to the heat medium flowing through the second circulation path. Therefore, by alternately switching the heat medium flow path 112 between the fourth state and the third state in accordance with the switching between the first state and the second state, it is possible to continuously recover cold heat generated when the adsorbent 181 desorbs the refrigerant by the heat medium flowing through the first circulation path.

[0063] Therefore, the refrigeration device 100 can continuously supply the heat medium heated by the recovered hot heat or cooled by the recovered cold heat to the first heat exchanger 142 connected to the first circulation flow path. The air that has exchanged heat with the heat medium in the first heat exchanger 142 is sent to a predetermined location by the first fan 143.

[0064] (3) Features (3-1) The heat source side circuit 101 of the refrigeration device 100 has a first pressure vessel 171 and a second pressure vessel 172. During operation of the refrigeration device 100, the first pressure vessel 171 contains high-pressure refrigerant discharged from the compressor 131, and the second pressure vessel 172 contains low-pressure refrigerant drawn into the compressor 131.

[0065] While the refrigerant flow path 111 is in the first state, the first pressure vessel 171 communicates with the first adsorption device 121, and the second pressure vessel 172 communicates with the second adsorption device 122. Therefore, a high-pressure refrigerant is present in the first space 164a of the first adsorption device 121, and a low-pressure refrigerant is present in the first space 164a of the second adsorption device 122.

[0066] While the refrigerant flow path 111 is in the second state, the first pressure vessel 171 communicates with the second adsorption device 122, and the second pressure vessel 172 communicates with the first adsorption device 121. Therefore, a low-pressure refrigerant is present in the first space 164a of the first adsorption device 121, and a high-pressure refrigerant is present in the first space 164a of the second adsorption device 122.

[0067] When the refrigerant flow path 111 switches from the first state to the second state, the first pressure vessel 171 stops communicating with the first adsorption device 121 and starts communicating with the second adsorption device 122. Before the refrigerant flow path 111 switches from the first state to the second state, high-pressure refrigerant is present in the first pressure vessel 171 and low-pressure refrigerant is present in the first space 164a of the second adsorption device 122. Therefore, when the refrigerant flow path 111 switches from the first state to the second state, the high-pressure refrigerant in the first pressure vessel 171 flows into the first space 164a of the second adsorption device 122 due to the pressure difference. As a result, the pressure in the first space 164a of the second adsorption device 122 increases. After the refrigerant flow path 111 switches from the first state to the second state, the high-pressure refrigerant discharged from the compressor 131 flows into the first space 164a of the second adsorption device 122. As a result, the pressure in the first space 164a of the second adsorption device 122 rises to the adsorption pressure, and the second adsorption device 122 starts to adsorb the refrigerant.

[0068] Therefore, after the refrigerant flow path 111 switches from the first state to the second state, the time required for the pressure in the first space 164a of the second adsorption device 122 to rise to the adsorption pressure is shortened by the high-pressure refrigerant in the first pressure vessel 171.

[0069] When the refrigerant flow path 111 switches from the first state to the second state, the second pressure vessel 172 stops communicating with the second adsorber 122 and starts communicating with the first adsorber 121. Before the refrigerant flow path 111 switches from the first state to the second state, high-pressure refrigerant is present in the first space 164a of the first adsorber 121, and low-pressure refrigerant is present in the second pressure vessel 172. Therefore, when the refrigerant flow path 111 switches from the first state to the second state, the high-pressure refrigerant in the first space 164a of the first adsorber 121 flows into the second pressure vessel 172 due to a pressure difference. As a result, the pressure in the first space 164a of the first adsorber 121 decreases. After the refrigerant flow path 111 switches from the first state to the second state, the refrigerant in the first space 164a of the first adsorber 121 is drawn into the compressor 131. As a result, the pressure in the first space 164a of the first adsorption device 121 drops to the desorption pressure, and desorption of the refrigerant in the first adsorption device 121 begins.

[0070] Therefore, after the refrigerant flow path 111 switches from the first state to the second state, the time required for the pressure in the first space 164a of the first adsorption device 121 to drop to the desorption pressure is shortened by the low-pressure refrigerant in the second pressure vessel 172.

[0071] When the refrigerant flow path 111 switches from the second state to the first state, the first pressure vessel 171 stops communicating with the second adsorber 122 and starts communicating with the first adsorber 121. Before the refrigerant flow path 111 switches from the second state to the first state, high-pressure refrigerant is present in the first pressure vessel 171 and low-pressure refrigerant is present in the first space 164a of the first adsorber 121. Therefore, when the refrigerant flow path 111 switches from the second state to the first state, the high-pressure refrigerant in the first pressure vessel 171 flows into the first space 164a of the first adsorber 121 due to a pressure difference. As a result, the pressure in the first space 164a of the first adsorber 121 increases. After the refrigerant flow path 111 switches from the second state to the first state, the high-pressure refrigerant discharged from the compressor 131 flows into the first space 164a of the first adsorber 121. As a result, the pressure in the first space 164a of the first adsorption device 121 rises to the adsorption pressure, and the first adsorption device 121 starts to adsorb the refrigerant.

[0072] Therefore, after the refrigerant flow path 111 switches from the second state to the first state, the time required for the pressure in the first space 164a of the first adsorption device 121 to rise to the adsorption pressure is shortened by the high-pressure refrigerant in the first pressure vessel 171.

[0073] When the refrigerant flow path 111 switches from the second state to the first state, the second pressure vessel 172 stops communicating with the first adsorption device 121 and starts communicating with the second adsorption device 122. Before the refrigerant flow path 111 switches from the second state to the first state, high-pressure refrigerant is present in the first space 164a of the second adsorption device 122, and low-pressure refrigerant is present in the second pressure vessel 172. Therefore, when the refrigerant flow path 111 switches from the second state to the first state, the high-pressure refrigerant in the first space 164a of the second adsorption device 122 flows into the second pressure vessel 172 due to the pressure difference. As a result, the pressure in the first space 164a of the second adsorption device 122 decreases. After the refrigerant flow path 111 switches from the second state to the first state, the refrigerant in the first space 164a of the second adsorption device 122 is drawn into the compressor 131. As a result, the pressure in the first space 164a of the second adsorption device 122 drops to the desorption pressure, and the desorption of the refrigerant in the second adsorption device 122 begins.

[0074] Therefore, when the refrigerant flow path 111 switches from the second state to the first state, the time required for the pressure in the first space 164a of the second adsorption device 122 to drop to the desorption pressure is shortened by the low-pressure refrigerant in the second pressure vessel 172.

[0075] As described above, the high-pressure refrigerant in the first pressure vessel 171 and the low-pressure refrigerant in the second pressure vessel 172 shorten the first period from the time when the refrigerant flow path 111 switches between the first state and the second state to the time when the pressure in the first space 164a of the first adsorption device 121 or the second adsorption device 122 reaches the adsorption pressure or the desorption pressure. During the first period, the pressure in the first space 164a of the first adsorption device 121 or the second adsorption device 122 is lower than the adsorption pressure, so that hot heat is not recovered by the heat medium in the second space 164b. Furthermore, during the first period, the pressure in the first space 164a of the first adsorption device 121 or the second adsorption device 122 is higher than the desorption pressure, so that cold heat is not recovered by the heat medium in the second space 164b. Therefore, the shorter the first period, the shorter the period during which the heat medium flowing through the heat medium passage 112 cannot collect hot energy and cold energy after the refrigerant passage 111 switches between the first state and the second state. In other words, the shorter the first period, the more efficiently the heat medium in the first adsorption device 121 and the second adsorption device 122 collects hot energy and cold energy.

[0076] Therefore, compared to a case where the heat source side circuit 101 does not have the first pressure vessel 171 and the second pressure vessel 172, the refrigeration device 100 of this embodiment can efficiently recover the warm heat generated when the adsorbent 181 adsorbs the refrigerant, or the cold heat generated when the adsorbent 181 desorbs the refrigerant, thereby suppressing a decrease in the capacity of the refrigeration device 100.

[0077] (3-2) The above-mentioned effects of the first pressure vessel 171 and the second pressure vessel 172 will be explained using Figures 4 and 5. Figure 4 is a time chart of the pressure and heat quantity of the first adsorption device 121 in the refrigeration system 100 as a comparative example. Figure 5 is a time chart of the pressure and heat quantity of the first adsorption device 121 in the refrigeration system 100 of the present embodiment. The only difference between the refrigeration system 100 as a comparative example and the refrigeration system 100 of the present embodiment is that in the refrigeration system 100 as a comparative example, the heat source side circuit 101 does not have the first pressure vessel 171 or the second pressure vessel 172.

[0078] The pressure time charts at the top of Figures 4 and 5 represent the change over time in pressure in the first space 164a of the first adsorption device 121. The heat quantity time charts at the bottom of Figures 4 and 5 represent the change over time in heat quantity, which is the amount of energy recovered to the heat medium in the second space 164b due to hot or cold heat generated when the refrigerant is adsorbed to or desorbed from the adsorbent 181 in the first space 164a of the first adsorption device 121. When the heat quantity is positive, hot heat is recovered to the heat medium in the second space 164b. When the heat quantity is negative, cold heat is recovered to the heat medium in the second space 164b.

[0079] 4 and 5 show a period in which the refrigerant flow path 111 is in the first state and a period in which the refrigerant flow path 111 is in the second state. During operation of the refrigeration device 100, operation in the first state and operation in the second state are alternately repeated. Hereinafter, one cycle of operation of the refrigeration device 100 refers to the period from the start of operation in the first state to the end of operation in the second state, which starts immediately after the end of operation in the first state. The time charts of the pressure and heat quantity of the second adsorption device 122 are shifted by half a cycle from the time charts of the pressure and heat quantity of the first adsorption device 121 shown in FIGS. 4 and 5.

[0080] 4 and 5 , the pressure in the first space 164a of the first adsorption device 121 increases from the desorption pressure to the adsorption pressure at the start of operation in the first state, and decreases from the adsorption pressure to the desorption pressure at the start of operation in the second state. During most of the first state, the pressure in the first space 164a of the first adsorption device 121 is equal to the adsorption pressure. During most of the second state, the pressure in the first space 164a of the first adsorption device 121 is equal to the desorption pressure.

[0081] In this embodiment, the heat source side circuit 101 includes the first pressure vessel 171 and the second pressure vessel 172, and therefore the first period is shortened. In FIGS. 4 and 5 , the first period corresponds to the period required for the pressure in the first space 164a of the first adsorption device 121 to increase from the desorption pressure to the adsorption pressure and the period required for the pressure to decrease from the adsorption pressure to the desorption pressure. The first period in this embodiment is shorter than the first period in the comparative example. Specifically, in FIG. 5 , the period required for the pressure in the first space 164a to increase from the desorption pressure to the adsorption pressure is shorter than the period required for the pressure in the first space 164a to increase from the desorption pressure to the adsorption pressure in FIG. 4 . Similarly, the period required for the pressure in the first space 164a to decrease from the adsorption pressure to the desorption pressure in FIG. 5 is shorter than the period required for the pressure in the first space 164a to decrease from the adsorption pressure to the desorption pressure in FIG. 4 .

[0082] After the refrigeration apparatus 100 starts operating in the first state, the heat quantity of the first adsorption device 121 increases due to the heat generated when the adsorbent 181 adsorbs the refrigerant. Thereafter, the heat quantity of the first adsorption device 121 reaches a positive peak near the point when the pressure in the first space 164a reaches the adsorption pressure, and then tends to gradually decrease. When the heat quantity of the first adsorption device 121 decreases to near zero, the control unit 105 controls the switching mechanism 135 to switch the refrigerant flow path 111 from the first state to the second state.

[0083] After the refrigeration apparatus 100 starts operating in the second state, the heat quantity of the first adsorption device 121 decreases due to the cold generated when the adsorbent 181 desorbs the refrigerant. Thereafter, the heat quantity of the first adsorption device 121 reaches a negative peak near the point when the pressure in the first space 164a reaches the desorption pressure, and then tends to gradually increase. When the heat quantity of the first adsorption device 121 increases to near zero, the control unit 105 controls the switching mechanism 135 to switch the refrigerant flow path 111 from the second state to the first state.

[0084] During one operation cycle of the refrigeration device 100, the amount of heat recovered by the heat medium flowing through the heat medium flow path 112 from the refrigerant flowing through the refrigerant flow path 111 due to the hot heat generated when the adsorbent 181 adsorbs the refrigerant is indicated by the area of ​​the first region S1 in FIG. 4 and the area of ​​the second region S2 in FIG. 5 . The areas of the first region S1 and the second region S2 correspond to the integrated values ​​of the heat quantity over time in the region where the heat quantity is equal to or greater than zero. When the amount of heat recovered by the heat medium during one operation cycle of the refrigeration device 100 is set to a predetermined value, the area of ​​the first region S1 in FIG. 4 and the area of ​​the second region S2 in FIG. 5 are equal. Furthermore, the first period in FIG. 5 is shorter than the first period in FIG. 4 . When the first period is shortened, the heat and cold energy recovery by the heat medium is more efficient, so the absolute value of the peak heat quantity increases, and one operation cycle of the refrigeration device 100 is shortened. Therefore, the period of one cycle in FIG. 5 is shorter than the period of one cycle in FIG. 4 .

[0085] Therefore, the refrigeration device 100 of this embodiment can increase the capacity per unit time compared to when the heat source side circuit 101 does not have the first pressure vessel 171 and the second pressure vessel 172.

[0086] Second Embodiment The basic configuration and operation of the refrigeration device 100 of the second embodiment are the same as those of the refrigeration device 100 of the first embodiment. The main difference between the refrigeration device 100 of the second embodiment and the refrigeration device 100 of the first embodiment is the heat source side circuit 101.

[0087] In the present embodiment, the heat source side circuit 101 further has an opening and closing mechanism provided on the refrigerant flow path 111. The opening and closing mechanism is provided at a position where, when the refrigerant flow path 111 is in a first state, the opening and closing mechanism allows or blocks the flow of refrigerant between the first pressure vessel 171 and the first adsorption device 121, and allows or blocks the flow of refrigerant between the second pressure vessel 172 and the second adsorption device 122. When the refrigerant flow path 111 is in a second state, the opening and closing mechanism is provided at a position where the opening and closing mechanism allows or blocks the flow of refrigerant between the second pressure vessel 172 and the first adsorption device 121, and allows or blocks the flow of refrigerant between the first pressure vessel 171 and the second adsorption device 122.

[0088] In this embodiment, the opening and closing mechanism includes a first valve 191 and a second valve 192. As shown in Fig. 6 , the first valve 191 is provided in the refrigerant flow path 111 between the first pressure vessel 171 and the switching mechanism 135. As shown in Fig. 6 , the second valve 192 is provided in the refrigerant flow path 111 between the second pressure vessel 172 and the switching mechanism 135.

[0089] The first valve 191 and the second valve 192 are, for example, electromagnetic valves, and are attached to a pipe in the refrigerant flow path 111 through which the refrigerant flows.

[0090] The first valve 191 and the second valve 192 allow or block the flow of refrigerant between the first adsorber 121 , the second adsorber 122 , the first pressure vessel 171 , and the second pressure vessel 172 .

[0091] When the refrigerant flow path 111 is in a first state, the first valve 191 allows or blocks the flow of refrigerant between the first pressure vessel 171 and the first adsorber 121. When the refrigerant flow path 111 is in a second state, the first valve 191 allows or blocks the flow of refrigerant between the first pressure vessel 171 and the second adsorber 122.

[0092] When the refrigerant flow path 111 is in the first state, the second valve 192 allows or blocks the flow of refrigerant between the second pressure vessel 172 and the second adsorption device 122. When the refrigerant flow path 111 is in the second state, the second valve 192 allows or blocks the flow of refrigerant between the second pressure vessel 172 and the first adsorption device 121.

[0093] The control unit 105 controls the opening and closing of the first valve 191 and the second valve 192 to allow or block the flow of refrigerant between the first adsorption device 121, the second adsorption device 122, the first pressure vessel 171, and the second pressure vessel 172.

[0094] In this embodiment, in the refrigerant flow path 111, the compressor 131, the first pressure vessel 171, and the second pressure vessel 172 are located between the first valve 191 and the second valve 192. Therefore, while the first valve 191 and the second valve 192 are closed, the flow path in the refrigerant flow path 111 connecting the compressor 131, the first pressure vessel 171, and the second pressure vessel 172 is blocked from the other flow paths.

[0095] When the first valve 191 and the second valve 192 are closed, the low-pressure refrigerant in the refrigerant flow path 111 from the second valve 192 to the suction side of the compressor 131 and the low-pressure refrigerant in the second pressure vessel 172 are drawn into the compressor 131, compressed, and discharged as high-pressure refrigerant. The high-pressure refrigerant discharged from the compressor 131 cannot pass through the first valve 191, and therefore does not reach the first adsorption device 121 when the refrigerant flow path 111 is in the first state, and does not reach the second adsorption device 122 when the refrigerant flow path 111 is in the second state. Therefore, most of the high-pressure refrigerant discharged from the compressor 131 is stored in the first pressure vessel 171.

[0096] On the other hand, when the first valve 191 and the second valve 192 are open, the low-pressure refrigerant in the refrigerant flow path 111 from the first adsorption device 121 or the second adsorption device 122 to the suction side of the compressor 131, and the low-pressure refrigerant in the second pressure vessel 172 are sucked into the compressor 131, compressed, and discharged as high-pressure refrigerant. The high-pressure refrigerant discharged from the compressor 131 passes through the first valve 191, and reaches the first adsorption device 121 when the refrigerant flow path 111 is in the first state, and reaches the second adsorption device 122 when the refrigerant flow path 111 is in the second state.

[0097] Therefore, the pressure of the refrigerant in the first pressure vessel 171 after a predetermined time has elapsed since the first valve 191 and the second valve 192 are closed is higher than the pressure of the refrigerant in the first pressure vessel 171 when the first valve 191 and the second valve 192 are open. Also, the pressure of the refrigerant in the second pressure vessel 172 after a predetermined time has elapsed since the first valve 191 and the second valve 192 are closed is lower than the pressure of the refrigerant in the second pressure vessel 172 when the first valve 191 and the second valve 192 are open.

[0098] As described above, when the refrigerant flow path 111 is switched between the first state and the second state, the higher the refrigerant pressure in the first pressure vessel 171, the shorter the time (first period) until the pressure in the first space 164a of the first adsorption device 121 or the second adsorption device 122 reaches the adsorption pressure. When the refrigerant flow path 111 is switched between the first state and the second state, the lower the refrigerant pressure in the second pressure vessel 172, the shorter the time (first period) until the pressure in the first space 164a of the first adsorption device 121 or the second adsorption device 122 reaches the desorption pressure. When the first period is shortened, one operating cycle of the refrigeration apparatus 100 is shortened.

[0099] Therefore, the refrigeration device 100 of this embodiment can increase the capacity per unit time compared to a case in which the heat source side circuit 101 does not have the first valve 191 and the second valve 192.

[0100] -Third embodiment- The basic configuration and operation of the refrigeration device 100 of the third embodiment are the same as those of the refrigeration device 100 of the first embodiment. The main difference between the refrigeration device 100 of the third embodiment and the refrigeration device 100 of the first embodiment is the heat source side circuit 101.

[0101] 7 , the heat source side circuit 101 further includes a bypass flow path 211 through which the refrigerant flows. The bypass flow path 211 connects the first adsorption device 121 and the second adsorption device 122 without passing through the compressor 131. The bypass flow path 211 connects, in the refrigerant flow path 111, the flow path between the first adsorption device 121 and the switching mechanism 135 and the flow path between the second adsorption device 122 and the switching mechanism 135.

[0102] The heat source side circuit 101 further includes a bypass valve 212. The bypass valve 212 is, for example, a solenoid valve. The bypass valve 212 is attached to a pipe in the bypass flow path 211 through which the refrigerant flows.

[0103] The control unit 105 controls the opening and closing of the bypass valve 212 to allow or block the flow of refrigerant in the bypass flow path 211 .

[0104] When the bypass valve 212 is closed and the refrigerant flow path 111 is in the first state, the inside of the first adsorption device 121 is in a high-pressure state and the inside of the second adsorption device 122 is in a low-pressure state. When the bypass valve 212 is closed and the refrigerant flow path 111 is in the second state, the inside of the first adsorption device 121 is in a low-pressure state and the inside of the second adsorption device 122 is in a high-pressure state. Therefore, when the bypass valve 212 is closed, the pressure in the first space 164a of the first adsorption device 121 and the pressure in the first space 164a of the second adsorption device 122 are different from each other.

[0105] When the bypass valve 212 is opened when switching the refrigerant flow path 111 between the first state and the second state, the first space 164a of the first adsorption device 121 and the first space 164a of the second adsorption device 122 are connected. This results in pressure equalization, which reduces the difference in pressure between the first space 164a of the first adsorption device 121 and the first space 164a of the second adsorption device 122. In other words, the difference in pressure between the first adsorption device 121 and the second adsorption device 122 after a predetermined time has elapsed since the bypass valve 212 was opened is smaller than the difference in pressure between the first adsorption device 121 and the second adsorption device 122 before the bypass valve 212 was opened.

[0106] When the bypass valve 212 is opened and pressure equalization is performed when the refrigerant flow path 111 switches from the first state to the second state, the pressure in the first space 164a of the first adsorption device 121 decreases and the pressure in the first space 164a of the second adsorption device 122 increases. Therefore, after switching from the first state to the second state, the time (first period) during which the pressure in the first space 164a of the first adsorption device 121 decreases to reach the desorption pressure and the time (first period) during which the pressure in the first space 164a of the second adsorption device 122 increases to reach the adsorption pressure are shortened.

[0107] When the bypass valve 212 is opened and pressure equalization is performed when the refrigerant flow path 111 switches from the second state to the first state, the pressure in the first space 164a of the first adsorption device 121 increases and the pressure in the first space 164a of the second adsorption device 122 decreases. Therefore, after switching from the second state to the first state, the time (first period) from when the pressure in the first space 164a of the first adsorption device 121 increases to when it reaches the adsorption pressure and the time (first period) from when the pressure in the first space 164a of the second adsorption device 122 decreases to when it reaches the desorption pressure are shortened. When the first period is shortened, one operating cycle of the refrigeration system 100 is shortened.

[0108] Therefore, the refrigeration device 100 of this embodiment can increase the capacity per unit time compared to a case in which the heat source side circuit 101 does not have the bypass flow path 211 and the bypass valve 212.

[0109] Fourth Embodiment The basic configuration and operation of the refrigeration device 100 of the fourth embodiment are the same as those of the refrigeration device 100 of the first embodiment. The main difference between the refrigeration device 100 of the fourth embodiment and the refrigeration device 100 of the first embodiment is the heat source side circuit 101.

[0110] 8 , the heat source side circuit 101 further includes a bypass flow path 211. The heat source side circuit 101 further includes a first valve 191, a second valve 192, and a bypass valve 212. The first valve 191 and the second valve 192 have the same functions as the first valve 191 and the second valve 192 in the second embodiment. The bypass flow path 211 and the bypass valve 212 have the same functions as the bypass flow path 211 and the bypass valve 212 in the third embodiment.

[0111] 9 , the control unit 105 further controls the first valve 191 and the second valve 192 to open or close, thereby allowing or blocking the flow of refrigerant between the first adsorption device 121, the second adsorption device 122, the first pressure vessel 171, and the second pressure vessel 172. In addition, the control unit 105 further controls the bypass valve 212 to open or close, thereby allowing or blocking the flow of refrigerant in the bypass flow path 211.

[0112] The control of the refrigeration apparatus 100 will be described with reference to the drawings. Fig. 10 is a flowchart of the control in one operation cycle of the refrigeration apparatus 100. Fig. 11 is a time chart of the control of the first valve 191, the second valve 192, the switching mechanism 135, and the bypass valve 212 by the control unit 105.

[0113] During operation of the refrigeration apparatus 100, the control unit 105 repeatedly executes steps S11 to S16 shown in Fig. 10. In the initial state before the start of step S11 in Fig. 10, the refrigerant flow path 111 is in the first state, and the first valve 191, the second valve 192, and the bypass valve 212 are closed.

[0114] In step S11, when the refrigerant flow path 111 is in the first state, the control unit 105 executes a first control to open the first valve 191 and the second valve 192. By opening the first valve 191 and the second valve 192, the control unit 105 allows the refrigerant to flow between the first adsorption device 121 and the first pressure vessel 171, and also allows the refrigerant to flow between the second adsorption device 122 and the second pressure vessel 172.

[0115] In step S12, the control unit 105 executes second control to close the first valve 191 and the second valve 192 and switch the refrigerant flow path 111 between the first state and the second state using the switching mechanism 135. In step S12, the second control switches the refrigerant flow path 111 from the first state to the second state.

[0116] In step S13, the control unit 105 performs pressure equalization by opening the bypass valve 212, and then executes third control to close the bypass valve 212. By opening the bypass valve 212, the control unit 105 allows the refrigerant to flow between the first adsorption device 121 and the second adsorption device 122. This performs pressure equalization, which reduces the difference between the refrigerant pressure in the first adsorption device 121 and the refrigerant pressure in the second adsorption device 122.

[0117] In step S14, when the refrigerant flow path 111 is in the second state, the control unit 105 executes a fourth control to open the first valve 191 and the second valve 192. By opening the first valve 191 and the second valve 192, the control unit 105 allows the refrigerant to flow between the first adsorption device 121 and the second pressure vessel 172, and also allows the refrigerant to flow between the second adsorption device 122 and the first pressure vessel 171.

[0118] In step S15, the control unit 105 executes second control to close the first valve 191 and the second valve 192 and switch the refrigerant flow path 111 between the first state and the second state using the switching mechanism 135. In step S15, the second control switches the refrigerant flow path 111 from the second state to the first state.

[0119] In step S16, the control unit 105 performs pressure equalization by opening the bypass valve 212, and then executes third control to close the bypass valve 212. By opening the bypass valve 212, the control unit 105 allows the refrigerant to flow between the first adsorption device 121 and the second adsorption device 122. This performs pressure equalization, which reduces the difference between the refrigerant pressure in the first adsorption device 121 and the refrigerant pressure in the second adsorption device 122.

[0120] During operation of the refrigeration apparatus 100, the control unit 105 executes step S16 and then step S11 again, thereby repeatedly executing steps S11-S16. The control unit 105 alternately executes the first control and the fourth control. The control unit 105 executes the second control and the third control between the first control and the fourth control. In the flowchart of FIG. 10 , the control unit 105 repeats one cycle of operation of the refrigeration apparatus 100, in which the control unit 105 executes the first control, the second control, the third control, the fourth control, the second control, the third control, and the first control in this order.

[0121] During the period between the start of step S11 and the start of step S12, the first valve 191 and the second valve 192 are open. During this period, the refrigerant flow path 111 is in the first state, so that the adsorbent 181 of the first adsorption device 121 adsorbs the refrigerant, and the adsorbent 181 of the second adsorption device 122 desorbs the refrigerant. As a result, in the first adsorption device 121, hot heat is recovered by the heat medium in the second space 164b, and in the second adsorption device 122, cold heat is recovered by the heat medium in the second space 164b.

[0122] During the period between the start of step S14 and the start of step S15, the first valve 191 and the second valve 192 are open. During this period, the refrigerant flow path 111 is in the second state, so that the adsorbent 181 of the first adsorption device 121 desorbs the refrigerant, and the adsorbent 181 of the second adsorption device 122 adsorbs the refrigerant. As a result, in the first adsorption device 121, cold energy is recovered by the heat medium in the second space 164b, and in the second adsorption device 122, hot energy is recovered by the heat medium in the second space 164b.

[0123] During operation of the refrigeration apparatus 100, the control unit 105 controls the first valve 191, the second valve 192, the switching mechanism 135, and the bypass valve 212 at the timings shown in FIG.

[0124] 11 shows the states of the first valve 191 and the second valve 192. During the "open" period, the first valve 191 and the second valve 192 are open. During the "closed" period, the first valve 191 and the second valve 192 are closed.

[0125] The time chart in the center of Figure 11 shows the state of the switching mechanism 135. During the "first state" period, the switching mechanism 135 is controlled so that the refrigerant flow path 111 is in the first state. During the "second state" period, the switching mechanism 135 is controlled so that the refrigerant flow path 111 is in the second state.

[0126] 11 shows the state of the bypass valve 212. During the "open" period, the bypass valve 212 is open. During the "closed" period, the bypass valve 212 is closed.

[0127] 11 shows one cycle of operation of the refrigeration device 100 and periods P1-P4. One cycle is made up of periods P1-P4. Period P1 is the period from the start of step S11 to the start of step S12. Period P2 is the period from the start of step S12 to the start of step S14. Step S13 is executed during period P2. Period P3 is the period from the start of step S14 to the start of step S15. Period P4 is the period from the start of step S15 to the start of step S11. Step S16 is executed during period P4.

[0128] During period P1, the first valve 191 and the second valve 192 are open. The control unit 105 opens the first valve 191 and the second valve 192 at the start of period P1. During period P1, the refrigerant flow path 111 is in the first state. During period P1, the bypass valve 212 is closed. During period P1, the adsorbent 181 of the first adsorption device 121 adsorbs the refrigerant, and the adsorbent 181 of the second adsorption device 122 desorbs the refrigerant.

[0129] During period P2, first valve 191 and second valve 192 are closed. Control unit 105 closes first valve 191 and second valve 192 at the start of period P2. During period P2, control unit 105 controls switching mechanism 135 to switch refrigerant flow path 111 from the first state to the second state. During period P2, control unit 105 opens bypass valve 212 for a predetermined time to perform pressure equalization. After pressure equalization is completed, control unit 105 closes bypass valve 212 before the end of period P2.

[0130] During period P3, the first valve 191 and the second valve 192 are open. The control unit 105 opens the first valve 191 and the second valve 192 at the start of period P3. During period P3, the refrigerant flow path 111 is in the second state. During period P3, the bypass valve 212 is closed. During period P3, the adsorbent 181 of the first adsorption device 121 desorbs the refrigerant, and the adsorbent 181 of the second adsorption device 122 adsorbs the refrigerant.

[0131] During period P4, first valve 191 and second valve 192 are closed. Control unit 105 closes first valve 191 and second valve 192 at the start of period P4. During period P4, control unit 105 controls switching mechanism 135 to switch refrigerant flow path 111 from the second state to the first state. During period P4, control unit 105 opens bypass valve 212 for a predetermined time to perform pressure equalization. After pressure equalization is completed, control unit 105 closes bypass valve 212 before the end of period P4.

[0132] The control unit 105 executes the second control and the third control so that the period during which the second control is executed and the period during which the third control is executed overlap each other. Specifically, the control unit 105 executes the second control and the third control based on any of the following first to third control patterns.

[0133] In the first control pattern, the control unit 105 simultaneously starts the second control and the third control. In this case, the control unit 105 first starts the second control by closing the first valve 191 and the second valve 192, and simultaneously starts the third control by opening the bypass valve 212. Next, the control unit 105 controls the switching mechanism 135 to switch the refrigerant flow path 111 between the first state and the second state, and ends the second control. Thereafter, the control unit 105 closes the bypass valve 212 and ends the third control. In the first control pattern, when executing the second control, the control unit 105 may close the first valve 191 and the second valve 192 and simultaneously control the switching mechanism 135 to switch the refrigerant flow path 111 between the first state and the second state.

[0134] In the second control pattern, the control unit 105 starts the third control after starting the second control and before ending the second control. In this case, the control unit 105 first starts the second control by closing the first valve 191 and the second valve 192. Next, the control unit 105 starts the third control by opening the bypass valve 212. Next, the control unit 105 controls the switching mechanism 135 to switch the refrigerant flow path 111 between the first state and the second state, and ends the second control. Thereafter, the control unit 105 closes the bypass valve 212 and ends the third control.

[0135] In the third control pattern, the control unit 105 starts the third control simultaneously with or after the second control ends. In this case, the control unit 105 first starts the second control by closing the first valve 191 and the second valve 192. Next, the control unit 105 controls the switching mechanism 135 to switch the refrigerant flow path 111 between the first state and the second state and ends the second control. Next, the control unit 105 starts the third control by opening the bypass valve 212. Thereafter, the control unit 105 closes the bypass valve 212 and ends the third control. In the third control pattern, the control unit 105 may control the switching mechanism 135 to switch the refrigerant flow path 111 between the first state and the second state and end the second control, and simultaneously open the bypass valve 212 and start the third control. In the third control pattern, when the second control is executed, the control unit 105 may close the first valve 191 and the second valve 192 and at the same time control the switching mechanism 135 to switch the refrigerant flow path 111 between the first state and the second state.

[0136] 11 , in periods P2 and P4, the control unit 105 switches the refrigerant flow path 111 between the first state and the second state, and simultaneously performs control to open the bypass valve 212. Therefore, the control unit 105 executes the second control and the third control based on the third control pattern.

[0137] The refrigeration device 100 of this embodiment can efficiently recover the hot heat generated when the adsorbent 181 adsorbs the refrigerant, or the cold heat generated when the adsorbent 181 desorbs the refrigerant.

[0138] Therefore, the refrigeration device 100 of this embodiment can increase the capacity per unit time compared to when the heat source side circuit 101 does not have the first valve 191, the second valve 192, the bypass flow path 211, and the bypass valve 212.

[0139] -Modifications- (1) Modification A In the second embodiment, the heat source side circuit 101 has, as an opening and closing mechanism, a first valve 191 and a second valve 192. The heat source side circuit 101 may have another opening and closing mechanism.

[0140] In this modification, the opening and closing mechanism includes a third valve 193 and a fourth valve 194. As shown in Fig. 12 , the third valve 193 is provided in the refrigerant flow path 111 between the first adsorption device 121 and the switching mechanism 135. As shown in Fig. 12 , the fourth valve 194 is provided in the refrigerant flow path 111 between the second adsorption device 122 and the switching mechanism 135.

[0141] The third valve 193 and the fourth valve 194 are, for example, electromagnetic valves and are attached to a pipe in the refrigerant flow path 111 through which the refrigerant flows.

[0142] The third valve 193 and the fourth valve 194 allow or block the flow of refrigerant between the first adsorber 121 , the second adsorber 122 , the first pressure vessel 171 , and the second pressure vessel 172 .

[0143] When the refrigerant flow path 111 is in the first state, the third valve 193 allows or blocks the flow of refrigerant between the first pressure vessel 171 and the first adsorber 121. When the refrigerant flow path 111 is in the second state, the third valve 193 allows or blocks the flow of refrigerant between the second pressure vessel 172 and the first adsorber 121.

[0144] When the refrigerant flow path 111 is in the first state, the fourth valve 194 allows or blocks the flow of refrigerant between the second pressure vessel 172 and the second adsorption device 122. When the refrigerant flow path 111 is in the second state, the fourth valve 194 allows or blocks the flow of refrigerant between the first pressure vessel 171 and the second adsorption device 122.

[0145] The control unit 105 controls the opening and closing of the third valve 193 and the fourth valve 194 to allow or block the flow of refrigerant between the first adsorption device 121, the second adsorption device 122, the first pressure vessel 171, and the second pressure vessel 172.

[0146] The third valve 193 and the fourth valve 194 of this modified example correspond to the first valve 191 and the second valve 192 of the second embodiment. When the refrigerant flow path 111 is in the first state, the third valve 193 is located between the first pressure vessel 171 and the first adsorber 121, similar to the first valve 191, and the fourth valve 194 is located between the second pressure vessel 172 and the second adsorber 122, similar to the second valve 192. When the refrigerant flow path 111 is in the second state, the third valve 193 is located between the second pressure vessel 172 and the first adsorber 121, similar to the second valve 192, and the fourth valve 194 is located between the first pressure vessel 171 and the second adsorber 122, similar to the first valve 191. Therefore, the third valve 193 and the fourth valve 194 have the same effects as the first valve 191 and the second valve 192.

[0147] Therefore, the refrigeration apparatus 100 of this modified example can increase the capacity per unit time compared to when the heat source side circuit 101 does not have the third valve 193 and the fourth valve 194.

[0148] This modification is also applicable to the fourth embodiment.

[0149] (2) Modification B The first pressure vessel 171 preferably holds therein a refrigerant at a pressure higher than the adsorption pressure during operation of the compressor 131. The adsorption pressure is the minimum value of the range of pressures at which the adsorbent 181 in the first adsorption device 121 and the second adsorption device 122 can adsorb the refrigerant.

[0150] As described in the second embodiment, the control unit 105 controls the timing of opening and closing the opening and closing mechanism of the heat source side circuit 101, thereby making it possible to hold refrigerant at a pressure higher than the adsorption pressure in the first pressure vessel 171. The opening and closing mechanism is, for example, the first valve 191 and the second valve 192 of the second embodiment, or the third valve 193 and the fourth valve 194 of Modification A.

[0151] (3) Modification C The second pressure vessel 172 preferably holds therein a refrigerant at a pressure lower than the desorption pressure during operation of the compressor 131. The desorption pressure is the maximum value of the range of pressures at which the adsorbent 181 in the first adsorption device 121 and the second adsorption device 122 can desorb the refrigerant.

[0152] As described in the second embodiment, the control unit 105 controls the timing of opening and closing the opening and closing mechanism of the heat source side circuit 101, thereby making it possible to hold refrigerant at a pressure lower than the desorption pressure in the second pressure vessel 172. The opening and closing mechanism is, for example, the first valve 191 and the second valve 192 of the second embodiment, or the third valve 193 and the fourth valve 194 of Modification A.

[0153] (4) Modification D In the heat source side circuit 101, it is preferable to set the internal volumes of the first pressure vessel 171 and the second pressure vessel 172. The internal volumes are the maximum volumes of refrigerant that can be held inside the first pressure vessel 171 and the second pressure vessel 172.

[0154] If the internal volumes of the first pressure vessel 171 and the second pressure vessel 172 are too large, the refrigerant pressures in the first pressure vessel 171 and the second pressure vessel 172 may not fall within a predetermined range during operation of the refrigeration system 100. The predetermined range is set based on, for example, the adsorption pressure and the desorption pressure. If the refrigerant pressures in the first pressure vessel 171 and the second pressure vessel 172 are not within the predetermined range, the time (first period) until the pressure in the first space 164a of the first adsorption device 121 and the second adsorption device 122 reaches the adsorption pressure or the desorption pressure after the refrigerant flow path 111 switches between the first state and the second state may become long.

[0155] In this modification, the internal volume of the first pressure vessel 171 is set so that the pressure of the refrigerant in the first pressure vessel 171 falls within a first target range when the compressor 131 operates to maximize the amount of refrigerant discharged per unit time while the refrigerant flow path 111 is in the first state or the second state. Specifically, the internal volume of the first pressure vessel 171 is set so that the pressure in the first pressure vessel 171 is equal to or greater than a predetermined value when the compressor 131 is operating at the maximum rotational speed. The first target range is set based on, for example, the adsorption pressure.

[0156] Similarly, the internal volume of the second pressure vessel 172 is set so that the pressure of the refrigerant in the second pressure vessel 172 falls within a second target range when the compressor 131 operates to maximize the amount of refrigerant discharged per unit time while the refrigerant flow path 111 is in the first state or the second state. Specifically, the internal volume of the second pressure vessel 172 is set so that the pressure in the second pressure vessel 172 is equal to or lower than a predetermined value when the compressor 131 is operating at the maximum rotation speed. The second target range is set based on, for example, the desorption pressure.

[0157] In this case, even if the compressor 131 is controlled to maximize the difference between the pressures of the high-pressure refrigerant and the low-pressure refrigerant and to maximize the amount of refrigerant discharged per unit time from the compressor 131, the pressures in the first pressure vessel 171 and the second pressure vessel 172 can be maintained within the target range. When the compressor 131 is controlled in this manner, for example, the pressure of the high-pressure refrigerant is 4.0 MPa and the pressure of the low-pressure refrigerant is 0.1 MPa.

[0158] Furthermore, if the internal volumes of the first pressure vessel 171 and the second pressure vessel 172 are too small, the amount of high-pressure refrigerant or low-pressure refrigerant that can be held in the first pressure vessel 171 and the second pressure vessel 172 decreases. Therefore, after the refrigerant flow path 111 switches between the first state and the second state, it may take a long time (first period) for the pressure in the first space 164a of the first adsorption device 121 and the second adsorption device 122 to reach the adsorption pressure or desorption pressure.

[0159] In this modification, at least one of an upper limit and a lower limit is set for the internal volumes of the first pressure vessel 171 and the second pressure vessel 172. By appropriately setting the internal volumes of the first pressure vessel 171 and the second pressure vessel 172, the first period is shortened, and the capacity per unit time of the refrigeration device 100 can be increased.

[0160] (5) Modification E In this modification, as shown in Fig. 13 , the heat source side circuit 101 further includes a first flow path 311. The first flow path 311 connects the first pressure vessel 171 with the suction side of the compressor 131. For example, as shown in Fig. 13 , the first flow path 311 connects the first pressure vessel 171 with the flow path between the second pressure vessel 172 and the compressor 131 in the refrigerant flow path 111.

[0161] During operation of the refrigeration system 100, the lubricating oil accumulated at the bottom of the first pressure vessel 171 passes through the first flow path 311 and is returned to the suction side of the compressor 131. The lubricating oil returned to the suction side of the compressor 131 flows into the compressor 131 and is supplied again to the sliding parts of the compressor 131.

[0162] The first flow path 311 may connect the first pressure vessel 171 and the compressor 131. In this case, the lubricating oil stored at the bottom of the first pressure vessel 171 passes through the first flow path 311 and is directly supplied to the sliding parts of the compressor 131.

[0163] In this modified example, a decrease in the capacity of the refrigeration device 100 caused by a shortage of lubricating oil supplied to the sliding parts of the compressor 131 and a decrease in the compression efficiency of the compressor 131 is suppressed.

[0164] (6) Modification F In the first embodiment, the casings 163 of the first adsorption device 121 and the second adsorption device 122 have inlets 163a connected to the refrigerant flow paths 111. The refrigerant in the refrigerant flow paths 111 flows into the casing 163 through the inlets 163a, and flows out from the casing 163 through the inlets 163a. ​​The inlets 163a function as both an inlet and an outlet for the refrigerant of the first adsorption device 121 and the second adsorption device 122.

[0165] In this modification, the casing 163 has an inlet and an outlet. In this case, the refrigerant flowing through the refrigerant flow path 111 passes through the inlet and flows into the interior of the casing 163, and the refrigerant inside the casing 163 passes through the outlet and flows out from the interior of the casing 163. The inlet functions as a refrigerant inlet for the first adsorption device 121 and the second adsorption device 122. The outlet functions as a refrigerant outlet for the first adsorption device 121 and the second adsorption device 122.

[0166] (7) Modification G The adsorbent used in the refrigeration device 100 is a metal-organic framework. However, a material other than a metal-organic framework may be used as the adsorbent. Examples of the material other than a metal-organic framework include activated carbon, a zeolite-based material, a silica-based material, and an alumina-based material.

[0167] (8) Modification H In the fourth embodiment, it is preferable that the control unit 105 further executes a fifth control, which controls the compressor 131 so that the internal pressures of the first pressure vessel 171 and the second pressure vessel 172 are within a predetermined range, when at least one of the first to fourth controls is executed.

[0168] In this modification, upper and lower limit values ​​for the internal pressure of each of the first pressure vessel 171 and the second pressure vessel 172 are set. The first pressure vessel 171 holds a high-pressure refrigerant therein. Therefore, the upper limit value for the internal pressure of the first pressure vessel 171 is set based on, for example, the rigidity of the first pressure vessel 171. The first pressure vessel 171 is connected to the first adsorber 121 or the second adsorber 122, which has an adsorbent that adsorbs the refrigerant. Therefore, the lower limit value for the internal pressure of the first pressure vessel 171 is set based on, for example, the adsorption pressure. The second pressure vessel 172 is connected to the first adsorber 121 or the second adsorber 122, which has an adsorbent that desorbs the refrigerant. Therefore, the upper limit value for the internal pressure of the second pressure vessel 172 is set based on, for example, the rigidity of the second pressure vessel 172. The second pressure vessel 172 holds a low-pressure refrigerant therein. Therefore, the lower limit value for the internal pressure of the second pressure vessel 172 is set based on, for example, the desorption pressure.

[0169] The control unit 105 controls the compressor 131 so that the internal pressure of each of the first pressure vessel 171 and the second pressure vessel 172 is within a range from an upper limit value to a lower limit value during a predetermined period of one operating cycle of the refrigeration device 100.

[0170] Two specific examples of the fifth control will be described using the time charts of Figures 14 and 15. The time charts of the first valve 191 and the second valve 192, the time chart of the switching mechanism 135, and the time chart of the bypass valve 212 shown in Figures 14 and 15 are the same as those in Figure 11.

[0171] (8-1) Control of the rotation speed of the compressor 131 In the first example, as shown in Fig. 14, the control unit 105 executes the fifth control by controlling the rotation speed of the compressor 131 without stopping the compressor 131. During operation of the refrigeration apparatus 100, the rotation speed of the compressor 131 is always greater than zero.

[0172] The control of the compressor 131 during periods P1 and P2 will be described with reference to the time chart in Fig. 14. Fig. 14 shows a time chart of the rotation speed of the compressor 131 and a time chart of the internal pressures of the first pressure vessel 171 and the second pressure vessel 172. In the time chart of the rotation speed of the compressor 131, "maximum" means the maximum value of the rotation speed of the compressor 131, and "minimum" means the minimum value of the rotation speed of the compressor 131. In the time chart of the internal pressures of the first pressure vessel 171 and the second pressure vessel 172, "upper limit value" means the upper limit value of the internal pressures of the first pressure vessel 171 and the second pressure vessel 172, and "lower limit value" means the lower limit value of the internal pressures of the first pressure vessel 171 and the second pressure vessel 172.

[0173] After the start of period P1, when the internal pressure of the first pressure vessel 171 falls below the lower limit or the internal pressure of the second pressure vessel 172 exceeds the upper limit, the control unit 105 increases the rotation speed of the compressor 131. As a result, the internal pressure of the first pressure vessel 171 increases and the internal pressure of the second pressure vessel 172 decreases.

[0174] Thereafter, during period P1, when the internal pressure of the first pressure vessel 171 exceeds the lower limit or the internal pressure of the second pressure vessel 172 falls below the upper limit, the control unit 105 reduces the rotation speed of the compressor 131. This reduces the rate at which the internal pressure of the first pressure vessel 171 increases and the rate at which the internal pressure of the second pressure vessel 172 decreases.

[0175] Then, after a predetermined period has elapsed, during period P1, the control unit 105 further reduces the rotation speed of the compressor 131. This further reduces the rate at which the internal pressure of the first pressure vessel 171 increases and the rate at which the internal pressure of the second pressure vessel 172 decreases. This prevents the internal pressure of the first pressure vessel 171 from exceeding the upper limit value and the internal pressure of the second pressure vessel 172 from falling below the lower limit value.

[0176] After that, from the end of period P1 until the end of period P2, the internal pressures of the first pressure vessel 171 and the second pressure vessel 172 are maintained within the range between the upper limit and the lower limit. If the internal pressure of the first pressure vessel 171 exceeds the upper limit or the internal pressure of the second pressure vessel 172 falls below the lower limit by the end of period P2, the rotation speed of the compressor 131 is further reduced.

[0177] The control of the compressor 131 during periods P3 and P4 is the same as the control of the compressor 131 during periods P1 and P2, respectively.

[0178] (8-2) Control of Start and Stop Timing of Compressor 131 In the second example, the control unit 105 executes the fifth control by controlling at least one of the timing to start the compressor 131 and the timing to stop the compressor 131, as shown in Fig. 15. While the compressor 131 is stopped, the rotation speed of the compressor 131 is zero.

[0179] Control of the compressor 131 during periods P1 and P2 will be described based on the time chart of Fig. 15. Fig. 15 shows a time chart of the compressor 131 and a time chart of the internal pressures of the first pressure vessel 171 and the second pressure vessel 172. In the time chart of the compressor 131, "operating" means that the compressor 131 is started and operating, and "stopped" means that the compressor 131 is stopped and not operating. In the time chart of the internal pressures of the first pressure vessel 171 and the second pressure vessel 172, the "upper limit value" and "lower limit value" are the same as those in the first example shown in Fig. 14.

[0180] After the start of period P1, when the internal pressure of the first pressure vessel 171 falls below the lower limit or the internal pressure of the second pressure vessel 172 exceeds the upper limit, the control unit 105 starts the compressor 131. As a result, the internal pressure of the first pressure vessel 171 increases and the internal pressure of the second pressure vessel 172 decreases.

[0181] Thereafter, during period P1, when the internal pressure of the first pressure vessel 171 reaches the upper limit or the internal pressure of the second pressure vessel 172 reaches the lower limit, the control unit 105 stops the compressor 131. As a result, the internal pressure of the first pressure vessel 171 stops increasing, and the internal pressure of the second pressure vessel 172 stops decreasing.

[0182] Thereafter, from the end of period P1 until the end of period P2, the internal pressure of first pressure vessel 171 is maintained near the upper limit value, and the internal pressure of second pressure vessel 172 is maintained near the lower limit value.

[0183] The control of the compressor 131 during periods P3 and P4 is the same as the control of the compressor 131 during periods P1 and P2, respectively.

[0184] Although the embodiments of the present disclosure have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the present disclosure as defined in the claims.

[0185] 100: Refrigeration device 105: Control unit 111: Refrigerant flow path 121: First adsorption device 122: Second adsorption device 131: Compressor 135: Switching mechanism 171: First pressure vessel 172: Second pressure vessel 181: Adsorbent 191: First valve 192: Second valve 193: Third valve 194: Fourth valve 211: Bypass flow path 212: Bypass valve 311: First flow path

[0186] US Patent Application Publication No. 2023 / 0417459

Claims

1. A refrigerant flow path (111) through which a refrigerant flows; a compressor (131) that sucks in and compresses a low-pressure refrigerant and discharges it as a high-pressure refrigerant; a first adsorber (121) and a second adsorber (122) having an adsorbent (181) that adsorbs and desorbs the refrigerant in accordance with changes in the refrigerant pressure, and that recovers hot heat generated when the adsorbent adsorbs the refrigerant and cold heat generated when the adsorbent desorbs the refrigerant; a switching mechanism (135); a first pressure vessel (171) connected to the discharge side of the compressor; a second pressure vessel (172) connected to the suction side of the compressor; an opening / closing mechanism provided on the refrigerant flow path and that allows or blocks the flow of refrigerant between the first adsorber, the second adsorber, the first pressure vessel, and the second pressure vessel; and a control unit (105) that controls the switching mechanism and the opening / closing mechanism, wherein the switching mechanism switches the refrigerant flow path between a first state in which the first pressure vessel and the first adsorber are connected to create a high-pressure state inside the first adsorber and the second pressure vessel and the second adsorber are connected to create a low-pressure state inside the second adsorber; and a second state in which the second pressure vessel and the first adsorber are connected to create a low-pressure state inside the first adsorber and the first pressure vessel and the second adsorber are connected to create a high-pressure state inside the second adsorber, wherein the control unit: a first control that controls the opening and closing mechanism to allow a refrigerant flow between the first adsorber and the first pressure vessel and to allow a refrigerant flow between the second adsorber and the second pressure vessel; a second control that controls the switching mechanism to switch the refrigerant flow path between the first state and the second state; and a third control that allows a refrigerant flow between the first adsorber and the second adsorber to reduce a difference between the pressure of the refrigerant in the first adsorber and the pressure of the refrigerant in the second adsorber. and a fourth control that controls the opening and closing mechanism to allow a refrigerant to flow between the first adsorber and the second pressure vessel, and to allow a refrigerant to flow between the second adsorber and the first pressure vessel.

2. The refrigeration device according to claim 1, wherein the opening and closing mechanism includes a first valve (191) and a second valve (192), the first valve being provided in the refrigerant flow path between the first pressure vessel and the first adsorber when the refrigerant flow path is in the first state, and the second valve being provided in the refrigerant flow path between the second pressure vessel and the second adsorber when the refrigerant flow path is in the first state.

3. The refrigeration device according to claim 2, wherein the control unit executes the first control by opening the first valve and the second valve when the refrigerant flow path is in the first state.

4. The refrigeration device according to claim 2 or 3, wherein the control unit executes the second control by closing the first valve and the second valve and controlling the switching mechanism to switch between the first state and the second state.

5. The refrigeration device according to any one of claims 2 to 4, wherein the control unit executes the fourth control by opening the first valve and the second valve when the refrigerant flow path is in the second state.

6. A refrigeration system as described in any one of claims 1 to 5, further comprising: a bypass flow path (211) connecting the first adsorber and the second adsorber without passing through the compressor; and a bypass valve (212) provided in the bypass flow path, wherein the control unit performs the third control by opening the bypass valve to reduce the difference and then closing the bypass valve.

7. The refrigeration device according to any one of claims 1 to 6, wherein the control unit executes the first control, then executes the second control and the third control, and then executes the fourth control.

8. The refrigeration device according to claim 7, wherein the control unit executes the second control and the third control so that a period during which the second control is executed and a period during which the third control is executed overlap each other.

9. The refrigeration device according to claim 7, wherein the control unit repeats a cycle of performing the first control, the second control, the third control, the fourth control, the second control, the third control, and the first control in this order.

10. A refrigeration device as described in any one of claims 1 to 9, wherein the control unit further executes a fifth control, which controls the compressor so that the internal pressure of the first pressure vessel falls within a predetermined range, when executing at least one of the first to fourth controls.

11. The refrigeration apparatus according to claim 10, wherein the control unit executes the fifth control by controlling the rotation speed of the compressor without stopping the compressor.

12. The refrigeration device according to claim 10 or 11, wherein the control unit executes the fifth control by controlling at least one of the timing to start the compressor and the timing to stop the compressor.

13. The refrigeration device according to any one of claims 1 to 12, wherein the adsorbent comprises a metal-organic framework containing metal ions and organic ligands.

14. The refrigeration device according to any one of claims 1 to 13, wherein the refrigerant flowing through the refrigerant flow path is selected from the group consisting of carbon dioxide, hydrocarbon refrigerants, ammonia, and water.

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