JP2019039574A - Air refrigerant refrigeration unit, air refrigerant refrigeration system and air refrigerant refrigeration method - Google Patents

Abstract

To enable removal of moisture and frost included in an air refrigerant during refrigeration operation in an air refrigerant refrigeration system.SOLUTION: An air refrigerant refrigeration unit related to one embodiment includes: an air refrigerant passage that includes a blowout port of an air refrigerant provided in a freezer and a suction port of the air refrigerant including air in the freezer and in which the air refrigerant circulates; a compressor provided in the air refrigerant passage to compress the air refrigerant sucked from the suction port to the air refrigerant passage; an expander provided in the air refrigerant passage to decompress and expand the air refrigerant compressed by the compressor and then return the air refrigerant to the freezer; a cold recovery heat exchanger provided in the air refrigerant passage to exchange heat between the air refrigerant compressed by the compressor and the air refrigerant sucked from the suction port to the air refrigerant passage; and a dehumidifier provided in the air refrigerant passage on the downstream side of the cold recovery heat exchanger and the upstream side of the compressor.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to an air refrigerant refrigeration apparatus, an air refrigerant refrigeration system, and an air refrigerant refrigeration method that use air as a refrigerant.

There is known a refrigeration system in which air, which is a natural refrigerant, is used as a refrigerant, and a frozen product can be frozen at an ultracold temperature of −60 ° C. or lower.
In Patent Documents 1 and 2, after the air refrigerant including the air in the freezer is compressed by the compressor, the air refrigerant is cooled by heat exchange with the air refrigerant on the upstream side of the compressor, and further, adiabatic expansion is performed by the expansion turbine. An air refrigerant refrigeration system that supplies the air refrigerant that has become to the freezer is disclosed.
As disclosed in Patent Documents 1 and 2, the heat exchange efficiency can be increased in the cooling system in which the ultra-low temperature air refrigerant is directly mixed with the air in the freezer. However, the water evaporated from the food to be frozen is mixed in the air refrigerant and may become frost, which may freeze and block the blowing nozzle and the circulation path of the air refrigerant. It is necessary to drive.

The refrigeration apparatus disclosed in Patent Literature 1 includes a dehumidification rotor that is coated with an adsorbent on its surface and is rotatable about the axis, and adsorbs moisture from the air refrigerant in one area of the rotating dehumidification rotor while the other area. Thus, the moisture adsorbed by the regenerated air is desorbed, so that the air refrigerant can be dehumidified during the freezing operation.
In the refrigeration system disclosed in Patent Document 2, an adsorbent is applied to a flow path of a heat exchanger that exchanges heat between the air refrigerant on the upstream side of the compressor and the air refrigerant on the downstream side of the compressor, and the air refrigerant The moisture contained in the water is adsorbed.

JP 2006-90599 A Japanese Patent No. 4185004

In the refrigeration system disclosed in Patent Document 1, since the air refrigerant around −30 ° C. taken out from the freezer is introduced into the dehumidification rotor, frost contained in the air refrigerant around −30 ° C. is frozen on the surface of the dehumidification rotor. As a result, the dehumidifying function of the dehumidifying rotor may be reduced. In general, the adsorbent applied to the surface of the dehumidifying rotor has a reduced adsorbing function in an environment of 0 ° C. or lower, and the air refrigerant may not be dehumidified.
The refrigeration system disclosed in Patent Document 2 also has the same problem as the refrigeration system disclosed in Patent Document 1 because the ultra-low temperature air refrigerant of −60 ° C. or lower in the freezer flows into the heat exchanger.

  In view of the above-described problems, an object of one embodiment is to enable moisture and frost contained in an air refrigerant to be removed during a freezing operation in an air refrigerant refrigeration system.

(1) An air refrigerant refrigeration apparatus according to an embodiment includes:
An air refrigerant passage through which the air refrigerant circulates, including an air refrigerant outlet provided in the freezer and an air refrigerant inlet including the air in the warehouse;
A compressor provided in the air refrigerant path, for compressing the air refrigerant sucked into the air refrigerant path from the suction port;
An expander provided in the air refrigerant path, for decompressing and expanding the air refrigerant compressed by the compressor and returning it to the freezer;
A cold recovery heat exchanger for exchanging heat between the air refrigerant provided in the air refrigerant path and compressed by the compressor and the air refrigerant sucked into the air refrigerant path from the suction port;
A dehumidifier provided in the air refrigerant path on the downstream side of the cold heat recovery heat exchanger and upstream of the compressor;
Is provided.

  According to the configuration of (1) above, the dehumidifier is provided on the downstream side in the flow direction of the air refrigerant from the cold heat recovery heat exchanger, and the air refrigerant heated by the cold heat recovery heat exchanger flows into the dehumidifier. Even if icing does not occur and the dehumidifier is a dehumidifier using an adsorbent, the adsorption function of the adsorbent does not decrease, so that moisture contained in the air refrigerant can be removed during the freezing operation.

(2) In one embodiment, in the configuration of (1),
The air refrigerant path does not have an outside air introduction portion between the air outlet and the inlet.
According to the configuration of (2), since the outside air is not introduced into the air refrigerant path, moisture contained in the outside air is not mixed. Therefore, an increase in the amount of moisture contained in the air refrigerant can be suppressed.

(3) In one embodiment, in the configuration of (1) or (2),
The air refrigerant whose temperature has been raised to 0 ° C. or higher by the cold heat recovery heat exchanger is introduced into the dehumidifier as a dehumidifying target.
According to the configuration of (3) above, since the air refrigerant heated to 0 ° C. or higher by the cold heat recovery heat exchanger is introduced into the dehumidifier as a dehumidification target, freezing does not occur in the dehumidifier, and the dehumidifier is Even in a dehumidifier using an adsorbent, the adsorption function of the adsorbent does not decrease, so that moisture contained in the air refrigerant can be removed during the freezing operation.

(4) In one embodiment, in any one of the configurations (1) to (3),
The dehumidifier has an adsorbent capable of adsorbing moisture, and is configured to dehumidify the air refrigerant by bringing the adsorbent into contact with the air refrigerant.
According to the configuration of (4) above, the dehumidifying effect of the air refrigerant can be improved by using the dehumidifier that dehumidifies with the adsorbent.

(5) In one embodiment, in the configuration of (4),
A regeneration air path for supplying regeneration air for regenerating the adsorbent to the dehumidifier is provided.
According to the configuration of (5) above, the adsorbent can be regenerated by removing the moisture adsorbed on the adsorbent by the regeneration air supplied from the regeneration air path to the dehumidifier. Further, since the regenerated air after being used for regeneration of the adsorbent is discarded, it does not become a load on the freezer.

(6) In one embodiment, in the configuration of (5),
The regeneration air path has a heater that preheats the regeneration air supplied to the dehumidifier.
According to the configuration of (6) above, the regeneration air supplied to the dehumidifier by the heater can be heated and the relative humidity of the regeneration air can be reduced, so that the regeneration effect of the adsorbent can be improved.

(7) In one embodiment, in the configuration of (5) or (6),
The regeneration air path includes a preheating heat exchanger that preheats the regeneration air by exchanging heat between the regeneration air supplied to the dehumidifier and the air refrigerant discharged from the compressor.
According to the configuration of (7), in the regeneration process of the dehumidifier, the regenerative air supplied to the dehumidifier can be preheated by the preheating heat exchanger and the relative humidity can be lowered, so that the regeneration effect of the dehumidifier can be improved. In addition, the heat source of the preheating heat exchanger can be covered by the retained heat of the air refrigerant discharged from the compressor, and the air refrigerant refrigeration apparatus is cooled by cooling the air refrigerant discharged from the compressor by the preheating heat exchanger. The thermal efficiency of can be improved.

(8) In one embodiment, in any one of the configurations (5) to (7),
The dehumidifier is configured by a dehumidification rotor that is configured to be rotatable about an axis and coated with an adsorbent,
The dehumidification rotor is disposed across the air refrigerant path and the regeneration air path.
The dehumidification rotor performs a dehumidification process in which the air refrigerant is dehumidified in an area disposed in the air refrigerant path, and an area in which moisture is adsorbed by the adsorbent in the dehumidification process is converted into a regeneration air path by rotating the dehumidification rotor. The regeneration process moves to the arranged area and desorbs the adsorbed moisture there.
According to the configuration of (8) above, since the adsorbent can be regenerated during the refrigeration operation of the air refrigerant refrigeration apparatus, the defrost operation becomes unnecessary and the refrigeration operation can be continued.

(9) In one embodiment, in any one of the configurations (5) to (7),
The dehumidifier is composed of a plurality of the dehumidifiers provided in parallel to the air refrigerant path,
Each of the plurality of dehumidifiers includes the regeneration air passage and is configured to selectively communicate with the air refrigerant passage or the regeneration air passage.
According to the configuration of (9) above, it is possible to perform a regeneration process in which at least one of the plurality of dehumidifiers dehumidifies the air refrigerant and desorbs moisture adsorbed by the other dehumidifiers. Therefore, since the regeneration process can be performed without stopping the refrigeration operation of the air refrigerant refrigeration apparatus, the defrost operation becomes unnecessary, and the refrigeration operation can be continued.

(10) In one embodiment, in the configuration of (8),
The regeneration air path has an induction fan that attracts the regeneration air to the dehumidification rotor on the outlet side of the dehumidification rotor.
According to the configuration of (10) above, the regeneration air passage does not become high pressure by supplying regeneration air to the dehumidification rotor by the attraction fan during the regeneration process. Therefore, since it can suppress that regeneration air flows into an air refrigerant path, the efficiency fall of the air refrigerant freezing apparatus which arises when high temperature regeneration air flows into the air refrigerant path by the side of a compressor can be controlled.

(11) An air refrigerant refrigeration system according to an embodiment includes:
The freezer;
An air refrigerant refrigeration apparatus having the configuration of any one of (1) to (10);
Is provided.
According to the configuration of (11) above, the dehumidifier is provided downstream of the cold heat recovery heat exchanger in the air refrigerant flow direction, and the air refrigerant heated by the cold heat recovery heat exchanger flows into the dehumidifier. Even when the surface of the rotor does not freeze and the dehumidifier uses an adsorbent, the adsorption function of the adsorbent does not deteriorate, so that moisture contained in the air refrigerant can be removed during the freezing operation.

(12) An air refrigerant refrigeration method according to an embodiment includes:
A circulation step of circulating the air refrigerant through an air refrigerant path having an air refrigerant inlet including the air refrigerant outlet and the air inside the refrigerator provided inside the freezer;
A compression step of compressing the air refrigerant sucked into the air refrigerant path from the suction port with a compressor;
An expansion step in which the air refrigerant compressed in the compression step is expanded under reduced pressure by an expander, cooled, and returned to the freezer;
A cold energy recovery step of exchanging heat between the air refrigerant compressed in the compression step and the air refrigerant sucked into the air refrigerant path from the suction port with a cold energy recovery heat exchanger;
A dehumidifying step of dehumidifying the air refrigerant from which the cold energy has been recovered by the cold heat recovery heat exchanger, with a dehumidifier;
Is provided.

  According to the method of (12), in the dehumidifying step, the air refrigerant whose cold heat has been recovered by the cold heat recovery heat exchanger and whose temperature has been raised is dehumidified by the dehumidifier, so that the dehumidifier does not cause icing and the dehumidifier Even if it is a dehumidifier using an adsorbent, since the adsorption function of the adsorbent does not deteriorate, moisture contained in the air refrigerant can be removed during the freezing operation.

(13) In one embodiment, in the method of (12),
In the circulation step,
The air refrigerant and the object to be frozen are in direct contact.
According to the above method (13), the air refrigerant and the object to be frozen are in direct contact with each other, so that the heat exchange efficiency between the air refrigerant and the object to be frozen can be improved.

(14) In one embodiment, in the method of (12) or (13),
The dehumidifier is configured by a dehumidification rotor that is configured to be rotatable about an axis and coated with an adsorbent,
A regeneration air path for supplying regeneration air for regenerating the adsorbent to the dehumidifying rotor;
The dehumidifying step includes
A dehumidifying step of dehumidifying the air refrigerant flowing through the air refrigerant path with the dehumidifying rotor;
A regeneration step in which the regeneration air is supplied from the regeneration air path to regenerate the adsorbent, and
By rotating the dehumidification rotor, the dehumidification step and the regeneration step are alternately performed in the adsorbent application region of the dehumidification rotor.

  According to the above method (14), in the dehumidification step, the dehumidification rotor rotates, and the dehumidification step and the regeneration step are alternately performed in the adsorbent application region of the dehumidification rotor. An adsorbent regeneration step can be performed.

(15) In one embodiment, in the method of (14),
Prior to the regeneration step, a preheating step of preheating the regeneration air by causing the regeneration air to exchange heat with the air refrigerant discharged from the compressor.
According to the above method (15), by performing the preheating step, the relative humidity of the regenerated air supplied to the dehumidifier can be reduced, so the adsorbent regeneration effect can be improved.

  According to one embodiment, in the air refrigerant refrigeration system, moisture and frost contained in the air refrigerant can be efficiently removed during the refrigeration operation.

1 is a system diagram of an air refrigerant refrigeration system according to an embodiment. 1 is a system diagram of an air refrigerant refrigeration system according to an embodiment. It is a systematic diagram of the dehumidifier which concerns on one Embodiment. It is process drawing of the air refrigerant freezing method which concerns on one Embodiment.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples.
For example, expressions expressing relative or absolute arrangements such as “in a certain direction”, “along a certain direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” are strictly In addition to such an arrangement, it is also possible to represent a state of relative displacement with an angle or a distance such that tolerance or the same function can be obtained.
For example, an expression indicating that things such as “identical”, “equal”, and “homogeneous” are in an equal state not only represents an exactly equal state, but also has a tolerance or a difference that can provide the same function. It also represents the existing state.
For example, expressions representing shapes such as quadrangular shapes and cylindrical shapes represent not only geometrically strict shapes such as quadrangular shapes and cylindrical shapes, but also irregularities and chamfers as long as the same effects can be obtained. A shape including a part or the like is also expressed.
On the other hand, the expressions “comprising”, “comprising”, “comprising”, “including”, or “having” one constituent element are not exclusive expressions for excluding the existence of other constituent elements.

1 and 2 show an air refrigerant refrigeration system 10 (10A, 10B) according to some embodiments.
In FIG.1 and FIG.2, the blower outlet 17a and the suction inlet 17b of the air refrigerant path 16 are provided in the inside of the freezer 14. As shown in FIG. The air refrigerant path 16 is provided with an air refrigerant refrigeration apparatus 12 (12A, 12B) that constitutes a Brayton cycle including a compressor 18, an expander 20, and a cold heat recovery heat exchanger 22. The compressor 18 sucks and compresses the internal air from the suction port 17b to the air refrigerant path 16. Inside the freezer 14, the relative humidity is almost 100% due to the water evaporated from the object to be frozen. The expander 20 decompresses and expands the air refrigerant compressed by the compressor 18 under a substantially adiabatic condition to cool to −60 ° C. or lower, and supplies the air refrigerant at −60 ° C. or lower to the inside of the freezer 14 from the outlet 17a. To do.

The cold heat recovery heat exchanger 22 exchanges heat between the air refrigerant compressed by the compressor 18 and the air refrigerant sucked into the air refrigerant path 16 from the suction port 17b, and heats the air refrigerant supplied to the compressor 18, By cooling the air refrigerant supplied to the expander 20, the thermal efficiency of the air refrigerant refrigeration apparatus 12 is improved.
A dehumidifier 24 is provided in the air refrigerant path 16 downstream of the cold heat recovery heat exchanger 22 and upstream of the compressor 18, and is included in the air refrigerant sucked from the suction port 17 b and heated by the cold heat recovery heat exchanger 22. Remove moisture.

  According to the above configuration, the dehumidifier 24 is provided downstream of the cold heat recovery heat exchanger 22 in the flow direction of the air refrigerant, and the air refrigerant heated by the cold heat recovery heat exchanger 22 flows in, so the dehumidifier 24 is frozen. Even if the dehumidifier 24 is a dehumidifier using an adsorbent, the adsorption function of the adsorbent does not decrease, so that moisture and frost contained in the air refrigerant can be removed during the freezing operation.

In one embodiment, as shown in FIGS. 1 and 2, the compressor 18 and the expander 20 are connected to a single output shaft 26a of the drive unit 26 and driven by the output shaft 26a.
In one embodiment, the drive unit 26 is, for example, a motor, and the compressor 18 and the expander 20 are each of a turbo type and are rotationally driven in conjunction with an output shaft 26a of the motor. As a result, the rotational force of the air refrigerant applied to the output shaft 26a by the decompression and expansion of the air refrigerant in the expander 20 assists the power of the drive unit 26, so that the thermal efficiency of the air refrigerant refrigeration apparatus 12 can be improved.

  In one embodiment, a primary cooler 28 is provided in the air refrigerant path 16 on the downstream side of the compressor 18. The high-temperature air refrigerant discharged from the compressor 18 is cooled by a cooling medium such as cooling water w in the primary cooler 28. Thereby, the thermal efficiency of the air refrigerant refrigeration apparatus 12 can be improved.

In one embodiment, the air refrigerant path 16 does not have an outside air introduction part between the air outlet 17a and the inlet 17b.
According to this embodiment, since the outside air is not introduced into the air refrigerant path 16, moisture contained in the outside air is not mixed. Therefore, an increase in the amount of moisture contained in the air refrigerant can be suppressed.

In one embodiment, an air refrigerant whose temperature has been raised to 0 ° C. or higher by the cold heat recovery heat exchanger 22 is introduced into the dehumidifier 24 as a dehumidifying target.
According to this embodiment, since the air refrigerant heated to 0 ° C. or higher by the cold heat recovery heat exchanger is introduced into the dehumidifier 24 as a dehumidification target, icing does not occur in the dehumidifier 24. Moreover, even if the dehumidifier 24 is a dehumidifier using an adsorbent, the air refrigerant is heated to 0 ° C. or higher, so that the adsorbent adsorption function does not deteriorate. Therefore, the dehumidifier 24 can maintain a dehumidifying function for moisture contained in the air refrigerant during the freezing operation.

In one embodiment, the dehumidifier 24 has an adsorbent capable of adsorbing moisture, and is configured to dehumidify the air refrigerant by bringing the adsorbent into contact with the air refrigerant.
According to this embodiment, the dehumidifying effect of the air refrigerant can be improved by using the dehumidifier that dehumidifies with the adsorbent.
As the adsorbing material, for example, an inorganic compound-based adsorbing material such as silica gel, zeolite, or activated carbon can be used.

In one embodiment, as shown in FIGS. 1 and 2, a regeneration air passage 30 for supplying regeneration air for regenerating the adsorbent to the dehumidifier 24 is provided. For example, outside air a is used as the regeneration air.
According to this embodiment, the adsorbent can be regenerated by removing the moisture adsorbed on the adsorbent by the regenerative air supplied from the regeneration air passage 30 to the dehumidifier 24. In addition, since the regeneration air after being used for regeneration of the adsorbent is exhausted outside the system, it does not become a load on the freezer 14.

In one embodiment, as shown in FIGS. 1 and 2, the regeneration air passage 30 includes a heater 32 that preheats regeneration air supplied to the dehumidifier 24.
According to this embodiment, since the regeneration air supplied to the dehumidifier 24 by the heater 32 can be heated and the relative humidity of the regeneration air can be lowered, the regeneration effect of the adsorbent can be improved.

In one embodiment, as shown in FIG. 2, in the air refrigerant refrigeration apparatus 12 (12 </ b> B), the regeneration air passage 30 includes a preheating heat exchanger 34. The preheating heat exchanger 34 preheats the regeneration air by exchanging heat between the regeneration air supplied to the dehumidifier 24 and the air refrigerant discharged from the compressor 18.
According to this embodiment, in the regeneration process of the dehumidifier 24, the regenerative air supplied to the dehumidifier 24 can be preheated by the preheating heat exchanger 34 and the relative humidity can be lowered, so that the regeneration effect of the dehumidifier can be improved. In addition, the heat source of the preheating heat exchanger 34 can be covered by the retained heat of the air refrigerant discharged from the compressor 18, and the air refrigerant discharged from the compressor 18 is cooled by the preheating heat exchanger 34. The thermal efficiency of the air refrigerant refrigeration apparatus 12 (12B) can be improved.

In one embodiment, as shown in FIGS. 1 and 2, the dehumidifier 24 is configured by a dehumidification rotor that is configured to be rotatable about an axis and to which an adsorbent is applied. The dehumidifying rotor is disposed across the air refrigerant path 16 and the regeneration air path 30. Of the dehumidifying rotor, a dehumidifying process for dehumidifying the air refrigerant is performed in an area disposed in the air refrigerant path 16, and an area where moisture is adsorbed by the adsorbent in the dehumidifying process is regenerated by rotating the dehumidifying rotor. A regeneration process for moving to the region arranged in the path 30 and desorbing the adsorbed moisture is performed.
According to this embodiment, since the adsorbent can be regenerated during the refrigeration operation of the air refrigerant refrigeration apparatus 12, the defrost operation becomes unnecessary, and the refrigeration operation can be continued.

In one embodiment, as shown in FIG. 3, the dehumidifier 24 includes a plurality of dehumidifiers 24 (24 a and 24 b) provided in parallel with the air refrigerant path 16. Each of the plurality of dehumidifiers 24 includes a regeneration air passage 30 (30a, 30b), and is configured to selectively communicate with the air refrigerant passage 16 or the regeneration air passage 30.
According to this embodiment, at least one dehumidifier among the plurality of dehumidifiers 24 (24a, 24b) performs a dehumidification process of the air refrigerant, and performs a regeneration process of desorbing moisture adsorbed by the other dehumidifiers. it can. Therefore, since the regeneration process can be performed without stopping the refrigeration operation of the air refrigerant refrigeration apparatus 12, the defrost operation becomes unnecessary, and the refrigeration operation can be continued.

In one embodiment, as shown in FIG. 3, the dehumidifier 24 includes a pair of dehumidifiers 24 (24 a and 24 b) provided in parallel to the air refrigerant path 16. A pair of air refrigerant paths 16 (16a, 16b) branched from the air refrigerant path 16 are connected to the pair of dehumidifiers 24 (24a, 24b), respectively. The pair of dehumidifiers 24 (24a, 24b) are connected to regeneration air passages 30 (30a, 30b) branched from the regeneration air passage 30, respectively.
On the upstream side and downstream side of the dehumidifier 24 (24a, 24b), switching valves 36 and 38 are provided in the pair of air refrigerant paths 16 and the pair of regenerative air paths 30 (30a, 30b), respectively.

  By controlling the opening and closing of the switching valves 36 and 38, in the dehumidifier 24 (24a, 24b), the air refrigerant path 16 (16a, 16b) and the regeneration air path 30 (30a, 30b) are alternately communicated to dehumidify. The process and the regeneration process are performed alternately. In FIG. 3, the switching valve 36 of the dehumidifier 24 (24a) is opened, the switching valve 38 is closed, the dehumidifying process is performed, the switching valve 36 of the dehumidifier 24 (24b) is closed, and the switching valve 38 is opened. The state where the regeneration process is performed is shown.

In one embodiment, as shown in FIGS. 1 and 2, a dehumidification rotor is used as the dehumidifier 24, and the regeneration air passage 30 is provided with an induction fan 40 on the outlet side of the dehumidification rotor. The regenerative air is attracted to the dehumidification rotor by the attraction fan 40.
According to this embodiment, the regeneration air path 30 does not become a high pressure by supplying regeneration air to the dehumidification rotor by the induction fan 40 during the regeneration process. Accordingly, since it is possible to suppress the regeneration air from flowing into the air refrigerant path 16, the air that is generated when high-temperature regeneration air (for example, the outside air a containing moisture) flows into the air refrigerant path 16 on the inlet side of the compressor 18. A reduction in efficiency of the refrigerant refrigeration apparatus 12 can be suppressed.

  The numerical value attached to each part of the air refrigerant path 16 in FIG.1 and FIG.2 shows an example of the temperature of the air refrigerant in each part.

As shown in FIGS. 1 and 2, the air refrigerant refrigeration system 10 (10A, 10B) according to some embodiments includes a freezer 14 and an air refrigerant refrigeration apparatus 12 (12A, 12B).
According to the air refrigerant refrigeration system 10, the dehumidifier 24 is provided downstream of the cold heat recovery heat exchanger 22 in the air refrigerant flow direction, and the air refrigerant heated by the cold heat recovery heat exchanger 22 flows into the dehumidifier 24. Therefore, icing does not occur on the surface of the dehumidifier 24, and even when the dehumidifier 24 is a dehumidifier using an adsorbent, the adsorbent adsorption function does not deteriorate, so that moisture contained in the air refrigerant is reduced during the freezing operation. Can be removed.

  As shown in FIG. 4, the air refrigerant refrigeration method according to the embodiment includes an air refrigerant outlet 16 a provided in the freezer 14 and an air refrigerant passage 16 having an air refrigerant inlet 17 b including air in the refrigerator. Air refrigerant is circulated (circulation step S10). The freezer 14 cools the object to be frozen, raises the temperature, contains the moisture evaporated from the object to be frozen, and the internal air having a relative humidity of approximately 100% is a compressor 18 provided in the air refrigerant path 16. Is sucked into the air refrigerant path 16 and compressed by the compressor 18 (compression step S12). The air refrigerant compressed by the compressor 18 is expanded under reduced pressure by the expander 20 under substantially adiabatic conditions, cooled to −60 ° C. or lower, and returned to the freezer 14 (expansion step S14). The inside of the freezer 14 is cooled to −60 ° C. or less by an ultra-low temperature air refrigerant.

  The air refrigerant compressed in the compression step S12 and the air refrigerant sucked into the air refrigerant path 16 from the suction port 17b are heat-exchanged by the cold recovery heat exchanger 22, and the air sucked into the air refrigerant path 16 from the suction port 17b. The refrigerant cools the high-temperature air refrigerant compressed in the compression step S12 (cold heat recovery step S16). Next, the air refrigerant whose temperature has been recovered from the cold heat recovery heat exchanger 22 and dehydrated is dehumidified by the dehumidifier 24 (dehumidification step S18).

  According to the above method, in the dehumidifying step S18, the air refrigerant whose temperature has been recovered by the cold heat recovery heat exchanger 22 and dehydrated is dehumidified by the dehumidifier 24, so that the dehumidifier 24 does not cause icing and the dehumidifier 24. Even if it is a dehumidifier using an adsorbent, since the adsorption function of the adsorbent does not deteriorate, moisture contained in the air refrigerant can be removed during the freezing operation.

In one embodiment, in the circulation step S <b> 10, the air refrigerant and the object to be frozen are in direct contact within the freezer 14.
According to this embodiment, since the air refrigerant and the object to be frozen are in direct contact, the heat exchange efficiency between the air refrigerant and the object to be frozen can be improved.

In one embodiment, the dehumidifier 24 is configured by a dehumidification rotor that is configured to be rotatable about an axis and is coated with an adsorbent, and a regeneration air passage 30 that supplies the dehumidification rotor with regeneration air that regenerates the adsorbent. Is provided. In the dehumidifying step S18, as shown in FIG. 4, first, the air refrigerant is dehumidified by the dehumidifying rotor in the area of the dehumidifying rotor into which the air refrigerant flowing through the air refrigerant path 16 flows (dehumidifying step S18a). Next, the area where the dehumidification rotor rotates and the moisture in the air refrigerant is adsorbed moves to the area where the regeneration air passage 30 flows, and the adsorbent that adsorbs the moisture is exposed to the regeneration air and releases the moisture to adsorb the adsorbent. Is reproduced (reproduction step S18c).
As described above, when the dehumidification rotor rotates, the dehumidification step S18a and the regeneration step S18c are alternately performed in the adsorbent application region of the dehumidification rotor.

  According to this embodiment, since the dehumidification rotor rotates in the dehumidification step S18, the dehumidification step S18a and the regeneration step S18c are alternately performed in the adsorbent application region of the dehumidification rotor, so that the dehumidification step S18a is continued. The adsorbent regeneration step S18c can be performed.

In one embodiment, as shown in FIG. 2, before the regeneration step S18c, the regeneration air is heat-exchanged with the air refrigerant discharged from the compressor 18 to preheat the regeneration air (preheating step S18b).
According to this embodiment, by performing the preheating step S18b, the relative humidity of the regeneration air supplied to the dehumidifier 24 can be lowered, so that the adsorbent regeneration effect can be improved.

  According to one embodiment, in the air refrigerant refrigeration system, moisture contained in the air refrigerant can be removed during the refrigeration operation.

10 (10A, 10B) Air refrigerant refrigeration system 12 (12A, 12B) Air refrigerant refrigeration apparatus 14 Freezer 16 (16a, 16b) Air refrigerant path 17a Air outlet 17b Air inlet 18 Compressor 20 Expander 22 Cold recovery heat exchanger 24 (24a, 24b) Dehumidifier 26 Drive unit 26a Output shaft 28 Primary cooler 30 (30a, 30b) Regenerative air passage 32 Heater 34 Preheating heat exchanger 36, 38 Switching valve 40 Induction fan a Outside air

Claims (15)

An air refrigerant passage through which the air refrigerant circulates, including an air refrigerant outlet provided in the freezer and an air refrigerant inlet including the air in the warehouse;
A compressor provided in the air refrigerant path, for compressing the air refrigerant sucked into the air refrigerant path from the suction port;
An expander provided in the air refrigerant path, for decompressing and expanding the air refrigerant compressed by the compressor and returning it to the freezer;
A cold recovery heat exchanger for exchanging heat between the air refrigerant provided in the air refrigerant path and compressed by the compressor and the air refrigerant sucked into the air refrigerant path from the suction port;
A dehumidifier provided in the air refrigerant path on the downstream side of the cold heat recovery heat exchanger and upstream of the compressor;
An air refrigerant refrigeration apparatus comprising:   2. The air refrigerant refrigeration apparatus according to claim 1, wherein the air refrigerant path does not include an outside air introduction portion between the air outlet and the suction port.   The air refrigerant refrigeration apparatus according to claim 1 or 2, wherein the air refrigerant whose temperature has been raised to 0 ° C or higher by the cold heat recovery heat exchanger is introduced into the dehumidifier as a dehumidification target.   4. The dehumidifier includes an adsorbent capable of adsorbing moisture, and is configured to dehumidify the air refrigerant by bringing the adsorbent into contact with the air refrigerant. The air refrigerant refrigeration apparatus according to claim 1.   The air refrigerant refrigeration apparatus according to claim 4, further comprising a regeneration air path for supplying regeneration air for regenerating the adsorbent to the dehumidifier.   The air refrigerant refrigeration apparatus according to claim 5, wherein the regeneration air path includes a heater that preheats the regeneration air supplied to the dehumidifier.   The regeneration air path includes a preheating heat exchanger that preheats the regeneration air by exchanging heat between the regeneration air supplied to the dehumidifier and the air refrigerant discharged from the compressor. Item 7. The air refrigerant refrigeration apparatus according to Item 5 or 6. The dehumidifier is configured by a dehumidification rotor that is configured to be rotatable about an axis and coated with an adsorbent,
The air refrigerant refrigeration apparatus according to any one of claims 5 to 7, wherein the dehumidifying rotor is disposed across the air refrigerant path and the regeneration air path. The dehumidifier is composed of a plurality of the dehumidifiers provided in parallel to the air refrigerant path,
8. Each of the plurality of dehumidifiers includes the regeneration air path, and is configured to be selectively communicated with the air refrigerant path or the regeneration air path. The air refrigerant refrigeration apparatus described in 1.   9. The air refrigerant refrigeration apparatus according to claim 8, wherein the regeneration air path has an induction fan that attracts the regeneration air to the dehumidification rotor on an outlet side of the dehumidification rotor. The freezer;
The air refrigerant refrigeration apparatus according to any one of claims 1 to 10,
An air refrigerant refrigeration system comprising: A circulation step of circulating the air refrigerant through an air refrigerant path having an air refrigerant inlet including the air refrigerant outlet and the air inside the refrigerator provided inside the freezer;
A compression step of compressing the air refrigerant sucked into the air refrigerant path from the suction port with a compressor;
An expansion step in which the air refrigerant compressed in the compression step is expanded under reduced pressure by an expander, cooled, and returned to the freezer;
A cold energy recovery step of exchanging heat between the air refrigerant compressed in the compression step and the air refrigerant sucked into the air refrigerant path from the suction port with a cold energy recovery heat exchanger;
A dehumidifying step of dehumidifying the air refrigerant from which the cold energy has been recovered by the cold heat recovery heat exchanger, with a dehumidifier;
An air refrigerant refrigeration method comprising: In the circulation step,
The air refrigerant refrigeration method according to claim 12, wherein the air refrigerant and the object to be frozen are in direct contact with each other. The dehumidifier is configured by a dehumidification rotor that is configured to be rotatable about an axis and coated with an adsorbent,
A regeneration air path for supplying regeneration air for regenerating the adsorbent to the dehumidifying rotor;
The dehumidifying step includes
A dehumidifying step of dehumidifying the air refrigerant flowing through the air refrigerant path with the dehumidifying rotor;
A regeneration step in which the regeneration air is supplied from the regeneration air path to regenerate the adsorbent, and
The air refrigerant refrigeration method according to claim 12 or 13, wherein the dehumidification step and the regeneration step are alternately performed in the adsorbent application region of the dehumidification rotor as the dehumidification rotor rotates.   15. The air refrigerant refrigeration method according to claim 14, further comprising a preheating step of preheating the regeneration air by exchanging heat of the regeneration air with the air refrigerant discharged from the compressor before the regeneration step. .

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