JP2005214568A - Refrigeration cycle device and its operating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigeration cycle device and its operating method capable of performing the defrosting operation without wetting loads in a chillroom and a freezer. <P>SOLUTION: A refrigerating machine wherein a freezer atmosphere is cooled by heat exchange between a refrigerant in a refrigerant circuit and the freezer atmosphere, comprises a casing having a discharge port on its upper part and accommodating an evaporator inside, an evaporator-side air blower for taking the freezer atmosphere into the casing and delivering the same toward the discharge port, a heater for heating the evaporator in defrosting operation, and a controller for controlling the motion of the evaporator-side air blower. The controller is constituted to stop the evaporator-side air blower in defrosting operation, to perform a first preliminary operation by blowing the air in a state of switching the air blowing direction of the evaporator-side air blower to the backward direction, and to perform the regular operation in a state of switching the air blowing direction of the air blower to the forward direction. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a refrigeration cycle apparatus and an operation method thereof.

  A refrigeration cycle apparatus such as a refrigeration apparatus or a refrigeration apparatus has a refrigerant circuit that forms a refrigeration cycle. Using an evaporator provided on the refrigerant circuit, the refrigerant circulating in the refrigerant circuit and the refrigeration chamber Heat exchange with the atmosphere or with the atmosphere in the freezer compartment is performed to cool the atmosphere in the refrigerator compartment or the atmosphere in the freezer compartment.

As such a refrigeration apparatus, for example, there is a refrigeration apparatus for land transportation described in Patent Document 1 described later.
This refrigeration system for land transportation cools the air in the freezer by an evaporator, and the cooled air is blown into the freezer compartment from above the evaporator unit (ie, above the evaporator) by a blower fan. Yes.

JP 2000-335308 A (paragraphs [0011] to [0016] and FIG. 1)

Here, in the refrigeration cycle apparatus, when the refrigerating room atmosphere or the freezing room atmosphere is cooled by the evaporator, the water contained in the atmosphere freezes and adheres to the evaporator as frost.
This frost gradually grows as the operation of the refrigeration cycle apparatus continues and prevents heat exchange by the evaporator. Therefore, in the refrigeration cycle apparatus, it is necessary to perform a defrost operation at an appropriate time to remove this frost.

During the defrosting operation, the evaporator is heated by a heater such as a coil heater, and thereby frost attached to the evaporator is melted.
However, since the surface temperature of the heater is as high as 500 ° C., part of the frost melted by the heater is evaporated to become water vapor.
The water vapor moves upward along with the heat convection and comes into contact with a member provided above the heater in the refrigeration cycle apparatus, so that condensation occurs on the surface of the member to form water droplets.
For this reason, in the configuration in which the air cooled by the evaporator is blown into the freezer compartment from above the evaporator as in the refrigeration apparatus for land transportation described in Patent Document 1, the blower fan or a member positioned above the blower fan is used. The adhering water droplets are carried into the freezer compartment on the airflow generated by the blower fan, and sometimes wet the load in the freezer compartment.

  The present invention has been made in view of such circumstances, and provides a refrigeration cycle apparatus and a method for operating the refrigeration cycle apparatus that do not wet the load in the refrigerator compartment or the freezer compartment even when the defrost operation is performed. With the goal.

In order to solve the above problems, the refrigeration cycle apparatus and the operation method thereof according to the present invention employ the following means.
That is, the refrigeration cycle apparatus according to the present invention uses an evaporator provided on the refrigerant circuit forming the refrigeration cycle, between the refrigerant circulating in the refrigerant circuit and the atmosphere in the refrigerator compartment, or the refrigerant. A refrigeration cycle apparatus that performs heat exchange with an atmosphere in a freezer compartment to cool the cold room atmosphere or the freezer compartment atmosphere, and is provided with a discharge port on the upper side and accommodates the evaporator inside Controlling the operation of the casing, a blower that takes the atmosphere in the refrigerator compartment or the freezer compartment into the casing and sends it to the outlet, a heater that heats the evaporator during defrost operation, and the blower The control device stops the blower device during the defrost operation, and after the defrost operation is finished, the control device After the first preliminary operation in which the air blowing direction of the device is switched in the reverse direction and the air blowing is performed, the normal air operation is performed by switching the air blowing direction of the air blowing device to the forward direction again. To do.

This refrigeration cycle apparatus constitutes a refrigeration apparatus used for cooling the indoor atmosphere of the refrigerator compartment and a refrigeration apparatus used for cooling the indoor atmosphere of the freezer compartment.
Also in this refrigeration cycle apparatus, during the defrost operation, the evaporator is heated by the heater, and the frost adhering to the evaporator is dissolved and removed. Is formed. Here, in this refrigeration cycle device, during the defrost operation, the operation of the blower is stopped by the control device, and the atmosphere heated by the heater (including water vapor generated by the evaporation of frost) is stored in the refrigerator compartment or in the freezer. It is not sent into the room.

In this refrigeration cycle device, after the defrost operation is completed, before returning to the normal operation, the air flow direction of the air blower is once switched to the reverse direction by the control device, and the air blower is operated in this state (first operation). One preliminary operation).
Then, since a downward airflow is generated in the casing, water droplets adhering to the evaporator and the member positioned above the evaporator drop on the casing below the airflow generated by the blower. This effect increases as the amount of air blown by the blower increases.

And after completion | finish of this 1st preliminary operation, the ventilation direction of an air blower is again switched to the positive direction by a control apparatus, and normal operation is performed.
At this time, since the water droplets attached to the evaporator and the member located above the first preliminary operation have been dropped below the casing in advance, compared to the case where the first preliminary operation is not performed, The amount of water drops carried on the airflow generated by the blower is carried into the refrigerator compartment or the refrigerator compartment.

  Further, in this refrigeration cycle apparatus, the control device reduces the air blowing amount of the air blower from that during the normal operation after switching the air blowing direction of the air blower to the positive direction after the completion of the first preliminary operation. After performing the 2nd preliminary operation which ventilates in the made state, you may be set as the structure which performs the said normal operation.

In this refrigeration cycle apparatus, after the first preliminary operation is completed, the air blower is operated in a state where the air flow is reduced before the air blow direction of the air blower is switched to the positive direction again and the normal operation is started. As a result (second preliminary operation), the wind pressure applied to the water droplets that remain without being dropped below the casing during the first preliminary operation is smaller than during normal operation.
Further, at the time of the second preliminary operation, similarly to the normal operation, a low-temperature atmosphere in which heat is exchanged by the evaporator is sent above the evaporator. Here, since the moisture is removed as water droplets or frost on the surface of the evaporator during heat exchange by the evaporator, the absolute humidity is lowered.

In this way, at the time of the second preliminary operation, since the atmosphere dried at a low temperature is sent above the evaporator at a low pressure, the water droplets above the evaporator do not move so much and are evaporated on the spot. Will be either frozen or frozen.
In this way, when the water droplets are evaporated or frozen in the second preliminary operation, even if the normal operation is restored after the second preliminary operation is completed, the air is sent into the refrigerator compartment or the freezer compartment by the air blower. It becomes difficult.

  In the refrigeration cycle apparatus, the casing may be provided with a damper device that regulates ventilation between the refrigerator compartment and the freezer compartment through the discharge port.

In this refrigeration cycle apparatus, during the defrost operation, or during the defrost operation and the first preliminary operation, the damper device allows the inside of the casing and the refrigerator compartment through the discharge port of the casing, or the inside of the casing and the freezer chamber through the discharge port. By restricting the air flow between them, the water vapor generated during the defrost operation is not sent to the refrigerator compartment or the freezer compartment, so that the entry of water vapor into the refrigerator compartment or the freezer compartment can be prevented.
Moreover, in this refrigeration cycle apparatus, since the damper device is provided on the refrigeration cycle device side, it is not necessary to provide the damper device in the refrigerator compartment or the freezer compartment.
For this reason, manufacture of a refrigerator compartment or a freezer compartment becomes easy, and a refrigerating-cycle apparatus can be installed also in the existing refrigerator compartment or freezer compartment, without performing the construction which installs a damper apparatus.

  An operation method of a refrigeration cycle apparatus according to the present invention includes an evaporator provided on a refrigerant circuit forming a refrigeration cycle, a casing in which the evaporator is housed and a discharge port is provided above, and the casing An air blower that takes in the refrigeration room atmosphere or the freezing room atmosphere and sends it to the discharge port; and a heater that heats the evaporator and performs defrosting, and the refrigerant circulating in the refrigerant circuit and the refrigeration room An operation method of a refrigeration cycle apparatus for performing heat exchange between an atmosphere or between the refrigerant and the freezer compartment atmosphere to cool the refrigerating room atmosphere or the freezer compartment atmosphere, and during the defrost operation, After the blower is stopped and the defrosting operation is completed, the first preliminary operation is performed in which the blowing direction of the blowing device is switched to the reverse direction to blow air, Switching the blowing direction of the fine said blower in a positive direction and performing normal operation.

The refrigeration cycle apparatus to which the operation method of the refrigeration cycle apparatus is applied constitutes a refrigeration apparatus used for cooling the indoor atmosphere of the refrigeration room and a refrigeration apparatus used for cooling the indoor atmosphere of the freezer room.
Also in this refrigeration cycle apparatus, during the defrost operation, the evaporator is heated by the heater, and the frost adhering to the evaporator is dissolved and removed. Is formed. Here, in this refrigeration cycle device, during the defrost operation, the operation of the blower is stopped by the control device, and the atmosphere heated by the heater (including water vapor generated by the evaporation of frost) is stored in the refrigerator compartment or in the freezer. It is not sent into the room.

In this operation method of the refrigeration cycle apparatus, after the defrost operation is completed, before returning to the normal operation, the air blowing direction of the air blower is once switched to the reverse direction, and the air blower is operated in this state (first preliminary operation). operation).
Then, since a downward airflow is generated in the casing, water droplets adhering to the evaporator and the member positioned above the evaporator drop on the casing below the airflow generated by the blower. This effect increases as the amount of air blown by the blower increases.
Then, after the end of the first preliminary operation, the control device switches the blowing direction of the blowing device to the positive direction again, and performs the normal operation.

  At this time, since the water droplets adhering to the evaporator and the member positioned above the first preliminary operation are dropped in the lower part of the casing in advance, the blower device is compared with the case where the first preliminary operation is not performed. The amount of water droplets carried in the refrigeration room or the refrigeration room by riding the airflow generated by is significantly reduced.

  In the operation method of the refrigeration cycle apparatus, after switching the blowing direction of the blower to the positive direction after the completion of the first preliminary operation, the amount of blown air of the blower is reduced in comparison with the normal operation. The normal operation may be performed after performing the second preliminary operation for blowing air.

In the operation method of the refrigeration cycle apparatus, after the first preliminary operation is completed, the air blowing amount of the air blower is reduced before switching to the normal operation again by switching the air blowing direction of the air blowing device. Since the air blower is operated, the wind pressure applied to the water droplets remaining without being dropped below the casing during the first preliminary operation is smaller than that during the normal operation.
Further, at the time of the second preliminary operation, similarly to the normal operation, a low-temperature atmosphere in which heat is exchanged by the evaporator is sent above the evaporator. Here, since the moisture is removed as water droplets or frost on the surface of the evaporator during heat exchange by the evaporator, the absolute humidity is lowered.

In this way, at the time of the second preliminary operation, since the atmosphere dried at a low temperature is sent above the evaporator at a low pressure, the water droplets above the evaporator do not move so much and are evaporated on the spot. Will be either frozen or frozen.
In this way, when the water droplets are evaporated or frozen in the second preliminary operation, even if the normal operation is restored after the second preliminary operation is completed, the air is sent into the refrigerator compartment or the freezer compartment by the air blower. It becomes difficult.

  According to the refrigeration cycle apparatus and the operation method thereof according to the present invention, even if the defrost operation is performed, it is not necessary to wet the load in the refrigerator compartment or the freezer compartment.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, as an example of the refrigeration cycle apparatus according to the present invention, a refrigeration apparatus 1 incorporated in a refrigeration container for land transportation or a refrigeration container for sea transportation will be described.

As shown in FIG. 1, the refrigeration apparatus 1 is provided in a container body 2 having a rectangular box shape of a refrigeration container for land transportation or a refrigeration container for sea transportation.
The container main body 2 constitutes a freezer compartment in which the load B is stored frozen. A heat insulating material is provided on a wall portion (including a bottom portion 2a described later) of the container main body 2 to prevent heat from entering and leaving the container main body 2 inside and outside.
The container body 2 includes a bottom 2a that forms an outer shell of the container body 2 and a floor 2b that is provided above the bottom 2a and on which the load B is placed.
Between the bottom 2a and the floor 2b, an air passage 2c that leads to an area where the refrigeration apparatus 1 is installed is formed. Further, an opening is provided in the floor 2b, and ventilation between the floor 2b and the ventilation path 2c is allowed through the opening.

In the present embodiment, the refrigeration apparatus 1 constitutes an outer wall at one end of the container body 2 in the longitudinal direction.
The refrigeration apparatus 1 includes a casing 6 having a hollow box shape and a refrigerant circuit 7.
Outer wall part 6a exposed to the outside of container body 2 among the wall parts of casing 6 constitutes a partition wall that partitions the inside and outside of container body 6, and is located inside container body 2 inside partition wall 6 in casing 6. The portion is isolated from the outside of the container body 2 by the outer wall portion 6a. The outer wall 6a is also provided with a heat insulating material to prevent heat from entering and leaving the container body 6 through the outer wall 6a.
Here, a recess 6b for housing a part of the members constituting the refrigerant circuit 7 is formed in the lower part of the outer wall 6a.

Among the wall portions of the casing 6, the inner wall portion 6 c facing the outer wall portion 6 a constitutes a partition that partitions the inside of the casing 6 and the space (loading chamber) in the container main body 2.
In the casing 6, an air passage 6 d that extends from the lower end to the upper end of the casing 6 is formed between the outer wall portion 6 a and the inner wall portion 6 c.
The lower end of the casing 6 is provided with a suction port 6e for taking the atmosphere in the container main body 2 into the air passage 6d. A discharge port 6f through which the atmosphere in the casing 6 is discharged is provided at the upper end of the casing 6.

Furthermore, a damper device 8 is provided at the upper portion of the casing 6 to regulate the ventilation between the inside of the casing 6 (inside the air passage 6d) and the cargo compartment of the container body 2 through the discharge port 6f.
In the present embodiment, the damper device 8 includes a door body 9a provided on the air passage 6d side of the upper end of the inner wall 6c of the casing 6 so as to be movable in the vertical direction, and the upper end of the door body 9a in FIG. As shown by a two-dot chain line, the container body 2 is moved between a state of contact with the ceiling (closed state) and a state where the upper end is separated from the ceiling (open state) as shown by a solid line in FIG. And a driving device 9b.
The drive device 9b includes, for example, a rack provided along the vertical direction with respect to the door body 9a, a pinion that meshes with the rack, and a motor that rotationally drives the pinion.

The refrigerant circuit 7 is provided in the casing 6 on the refrigerant flow path through which the refrigerant is circulated, and performs an heat exchange between the refrigerant and the atmosphere in the casing 6 to cool the atmosphere in the casing 6. The compressor 12 that pressurizes the refrigerant, the condenser 13 that exchanges heat between the refrigerant and the atmosphere outside the container body 2 to release the heat of the refrigerant to the outside of the refrigerant circuit 7, and expands and cools the refrigerant An electronic expansion valve (not shown) is provided in this order.
Among these members, the compressor 12, the condenser 13, and the electronic expansion valve are provided in the recess 6 b of the casing 6.
The recess 6b of the casing 6 is provided with a condenser air blower 14 for supplying outside air to the condenser 13 to promote heat exchange.

On the other hand, in the casing 6, an evaporator blower 16 that takes in the atmosphere in the container body 2 into the casing 6 and sends it out toward the discharge port 6 f is provided above the evaporator 11.
A three-phase AC fan motor is used as the blower 16. This is because the three-phase AC fan motor can easily rotate the fan in the reverse direction only by converting the phase of the electric power input to each coil from the normal phase to the reverse phase (reversing the blowing direction). This is because the later-described control can be easily realized.
A heater 17 that heats the evaporator 11 during the defrost operation is provided below the evaporator 11. For example, a coil heater is used as the heater 17.

  Here, in the refrigeration apparatus 1, a drain receiver D that collects water droplets dropped from above is provided below the heater 17. In the present embodiment, a portion of the outer wall 6a of the casing 6 that is located below the heater 17 is provided so as to protrude below the heater 17, and a drain receiver D is provided in this portion. Further, a flap F that receives water droplets dropped from above is provided on the drain wall D below the heater 17 on the inner wall 6c of the casing 6. The flap F is provided so as to be inclined from the inner wall 6c side toward the drain receiver D side, and at the lower end, the water droplets flowing toward the drain receiver D side on the flap F are collected. A kite is provided. The ridge is inclined along the longitudinal direction thereof, and a conduit P for guiding water droplets flowing into the ridge to the drain receiver D is provided at the lowermost portion of the ridge. In addition, the flap F is provided apart from the drain receiver D, and the ventilation | gas_flowing through these is accept | permitted.

Further, the refrigeration apparatus 1 is provided with a control device 18 for controlling the operation of the compressor 12, the operation of the evaporator blower 16, the operation of the heater 17, and the operation of the damper device 8.
The control device 18 performs normal phase conversion (rotation in a direction in which air is blown toward the upper side of the casing 6) by performing phase conversion of electric power input to each coil of the fan motor constituting the blower device 16. Switching between reverse rotation (rotation in a direction in which air is blown toward the lower side of the casing 6) is performed.

Further, the refrigeration apparatus 1 includes an inlet side temperature sensor 19a that measures the ambient temperature near the suction port 6e of the ventilation path 6d, and an outlet side temperature sensor 19b that measures the ambient temperature near the discharge port 6f of the ventilation path 6d. Is provided.
The control device 18 is configured to control the operation of the evaporator-side air blower 16 based on the measured values of the inlet-side temperature sensor 19a and the outlet-side temperature sensor 19b.

  Here, in the present embodiment, in the refrigeration apparatus 1, among the members in the casing 6, at least the surface of a member (including the inner surface of the casing 6) located at the same height as the evaporator 11 or above the evaporator 11. Has been subjected to water repellent treatment such as fluororesin coating.

  The refrigeration apparatus 1 configured as described above opens the door body 9a of the damper apparatus 8 during normal operation and allows ventilation between the inside of the casing 6 and the cargo compartment of the container body 2 through the discharge port 6f. . Then, by operating the evaporator blower 16 in this state, the air passage 2c, the suction port 6e of the casing 6, the air passage 6d, the discharge port 6f, and the cargo chamber are circulated in this order from the cargo chamber of the container body 2. Generate airflow. Here, in the fan motor constituting the evaporator blower 16, the rotation of the fan in the direction that generates the airflow in this direction is defined as normal rotation.

And in the state which generated the airflow of such direction in the ventilation path 6d of the casing 6, by operating the compressor 12 of the refrigerant circuit 7, a refrigeration cycle is formed and the inside of the ventilation path 6d by the evaporator is formed. Cool the atmosphere. Thereby, the atmosphere cooled in the ventilation path 6d circulates in the container main body 2, and the atmosphere in the container main body 2 is maintained at the target temperature.
In the present embodiment, the operation of the refrigeration apparatus 1 is controlled by the controller 18 so that the atmosphere in the container body 6 is maintained at −25 ° C.

Hereinafter, the operation of the refrigerant circuit 7 will be described.
In the refrigerant circuit 7, the gaseous refrigerant that has been pressurized by the compressor 12 to become high-temperature and high-pressure is sent to the condenser 13, and heat exchange is performed between the refrigerant and the atmosphere outside the container body 2 by the condenser 13. The refrigerant is cooled, condensed and liquefied.
The liquid refrigerant condensed and liquefied by the condenser 13 in this manner is decompressed by an electronic expansion valve provided on the downstream side of the condenser 13 in the refrigerant circuit 7 to become a low-temperature and low-pressure liquid refrigerant.
This low-temperature and low-pressure liquid refrigerant is sent to the evaporator 11 to exchange heat with the atmosphere in the air passage 6d.
By passing through the evaporator 11, the refrigerant takes heat from the atmosphere in the air passage 6d and evaporates, whereby the atmosphere in the air passage 6d is cooled.
The gaseous refrigerant that has passed through the evaporator 11 is sent to the compressor 12, is again pressurized by the compressor 12, is sent to the condenser 13, and the above process is repeated during operation of the compressor 12.

Here, the evaporator-side air blower 16 is configured so that the control device 18 can switch the rotational speed of the fan between two stages of high speed and low speed.
The control device 18 basically promotes cooling of the atmosphere in the container body 6 by operating the evaporator-side air blower 16 at a high speed when the atmosphere temperature in the container body 6 is higher than a predetermined temperature. After the atmosphere in the container body 6 reaches a predetermined temperature, the evaporator-side air blower 16 is operated at a low speed to maintain the atmosphere temperature in the container body 6 at the target temperature.

  In the present embodiment, the control device 18 detects the ambient temperature in the vicinity of the suction port 6e of the ventilation path 6d measured by the inlet side temperature sensor 19a and the vicinity of the discharge port 6f of the ventilation path 6d measured by the outlet side temperature sensor 19b. If any one of the ambient temperatures exceeds −5 ° C., the evaporator-side air blower 16 is operated at a high speed so that the ambient temperature in the container body 6 decreases to the target temperature.

Also in this refrigeration apparatus 1, since frost adheres to the evaporator 11 by continuing the operation for a long time, the defrost operation is performed at an appropriate time (for example, every 3 to 12 hours).
Here, in this refrigeration apparatus 1, the flow of control by the control apparatus 18 when performing the defrost operation is shown in the flowchart of FIG.
First, the state where the normal operation is performed (step S1) shifts to the defrost operation (step S2).

During the defrost operation, the control device 18 operates the drive device 9b of the damper device 8 until the upper end of the door body 9a comes into contact with the ceiling of the container body 2 as shown in FIG. ) To raise and regulate the ventilation between the inside of the casing 6 (inside the ventilation path 6d) and the cargo compartment of the container body 2 through the discharge port 6f.
Further, the control device 18 stops the operation of the compressor 12 to stop the circulation of the refrigerant in the refrigerant circuit 7 and also stops the operation of the evaporator-side air blower 16 to stop the heat exchange by the evaporator 11. Let
In this state, the control device 18 energizes the heater 17 to overheat and melt the frost attached to the evaporator 11 by the heater 17.

Here, since the surface temperature of the heater 17 at this time rises to about 500 ° C., a part of the frost melted by the heater 17 is evaporated to become water vapor (the temperature of the water vapor is about 60 to 70 ° C.). Is).
The water vapor moves upward of the evaporator 11 in the casing 6 by heat convection. The member in the casing 6 remains cooled by normal operation and is at a temperature lower than at least water vapor. For this reason, the water vapor that has moved to the upper part of the casing 6 is cooled by a member (including the inner surface of the casing 6) located at the same height as the evaporator 11 or above the evaporator 11 in the casing 6. Condensation on the surface.

  Here, in the present embodiment, in the refrigeration apparatus 1, at least the surface of the member in the casing 6 that is at the same height as the evaporator 11 or located above the evaporator 11 is subjected to water repellent finishing. Therefore, when the condensation progresses and the water droplets increase to some extent, the water droplets fall from these members and are received by the drain receiver D and the flap F below the heater 7, and finally the drain receiver D. Collected.

Thus, after the frost adhering to the evaporator 11 is removed, the control apparatus 18 stops the heater 17 and complete | finishes a defrost driving | operation (step S3).
Here, for example, the control device 18 is configured to stop the defrosting operation after a sufficient time has passed for frost removal after the defrosting operation is started.

  In the refrigeration apparatus 1 according to the present embodiment, after the defrost operation is completed, the control device 18 does not return to the normal operation as it is, but the first preliminary operation (steps S4 and S5) and the second preliminary operation. After the operation (steps S6 and S7), the normal operation is restored. Hereinafter, the control in each of the first preliminary operation and the second preliminary operation will be described in detail.

  As shown in the flowchart of FIG. 4, in the first preliminary operation, the control device 18 first operates the compressor 12 to start circulation of the refrigerant in the refrigerant circuit 7 for a predetermined time (in this embodiment, 4 minutes). (Step S11). As a result, the refrigerant superheated by the heater 17 in the evaporator 11 is pushed away, and the temperature of the evaporator 11 is lowered to a temperature that does not hinder normal operation.

After the predetermined time has elapsed and the compressor 12 has been stopped (step S12), the control device 18 reversely rotates the fan motor of the evaporator-side air blower 16 to temporarily blow the air from the evaporator-side air blower 16. The direction is switched to the opposite direction (step S13).
In this state, the control device 18 rotates the fan motor of the evaporator-side air blower 16 at a high speed for a predetermined time (in this embodiment, 1 minute) (step S14).
Then, since an air flow is generated in the casing 6 in the downward direction of the air passage 6d, as shown in FIG. 2, water droplets adhering to the evaporator 11 and the members positioned above the evaporator 11 It rides on the airflow generated by the blower 16 and falls below the casing 6 and is collected in the drain receiver D. This effect increases as the amount of air blown by the evaporator-side air blower 16 increases.

After the evaporator side air blower 16 stops and the first preliminary operation ends (step S15), the control device 18 switches the air blowing direction of the evaporator side air blower 16 to the positive direction again (step S16).
In this state, the control device 18 operates the drive device 9b of the damper device 8 to lower the door body 9a as shown in FIG. 1, and within the casing 6 (in the air passage 6d) through the discharge port 6f. And ventilation between the container body 2 and the cargo compartment.
Further, the control device 18 starts the operation of the compressor 12 to start circulation of the refrigerant in the refrigerant circuit 7.
Then, the control device 18 is operated for a predetermined time (10 minutes in the present embodiment) in a state where the amount of air blown by the evaporator-side air blower 16 is reduced from that during normal operation (step S17, second preliminary operation).

Here, the water droplets adhering to the evaporator 11 and the member located above the evaporator 11 are previously dropped below the casing 6 by the first preliminary operation.
For this reason, even if the evaporator-side air blower 16 is operated in the second preliminary operation with its air blowing direction switched to the positive direction, almost no water droplets are carried into the container main body 2 or the evaporator side The amount of water droplets carried in the container main body 2 on the airflow generated by the blower 16 is significantly reduced.

Further, since the evaporator-side air blower 16 is operated at a low speed during the second preliminary operation, the wind pressure applied to the remaining water droplets without being dropped below the casing 6 during the first preliminary operation is smaller than that during the normal operation. .
Further, at the time of the second preliminary operation, similarly to the normal operation, a low-temperature atmosphere in which heat is exchanged by the evaporator 11 is sent above the evaporator 11. Here, since the moisture is removed as water droplets or frost on the surface of the evaporator during heat exchange by the evaporator, the absolute humidity is lowered.

In this way, at the time of the second preliminary operation, since the atmosphere dried at a low temperature is sent above the evaporator at a low pressure, the water droplets above the evaporator do not move so much and are evaporated on the spot. Will be either frozen or frozen.
Then, as the water droplets are evaporated or frozen in the second preliminary operation in this way, even if the normal operation is restored after the completion of the second preliminary operation, the air is blown into the cargo compartment of the container main body 2 by the air blower. It becomes difficult to be.

  Further, by performing the second preliminary operation for 10 minutes in this manner, the inside of the casing 6 where the temperature has been increased by the heat of the heater 7 is cooled to a temperature at which normal operation is not hindered.

And after finishing the 2nd preliminary operation in this way, the control apparatus 18 makes the freezing apparatus 1 transfer to a normal operation (step S19).
Thereafter, the control device 18 shifts to control during normal operation.
Specifically, both the ambient temperature near the suction port 6e of the ventilation path 6d measured by the inlet side temperature sensor 19a and the ambient temperature near the discharge port 6f of the ventilation path 6d measured by the outlet side temperature sensor 19b. When the temperature is −5 ° C. or lower, the evaporator-side air blower 16 is operated at a low speed so that the atmosphere in the container body 6 is maintained at the target temperature (step S20).
On the other hand, the control device 18 determines the ambient temperature near the suction port 6e of the ventilation path 6d measured by the inlet side temperature sensor 19a, and the ambient temperature near the discharge port 6f of the ventilation path 6d measured by the outlet side temperature sensor 19b. If either of them exceeds -5 ° C, the evaporator-side air blower 16 is operated at a high speed so that the atmosphere in the container body 6 is cooled to the target temperature (step S21).

  As described above, according to the refrigeration apparatus 1, the first and second preliminary operations are performed after the defrost operation, so that the evaporator-side air blower 16 is generated when the normal operation is performed after the defrost operation. It is possible to prevent the load B in the container main body 2 from getting wet because the amount of water droplets carried on the air current is not carried into the container main body 2 or is carried by the air flow is significantly reduced.

Further, in the refrigeration apparatus 1, ventilation between the inside of the casing 6 and the inside of the container main body 2 through the discharge port 6 f of the casing 6 is performed by the damper device 8 at the time of the defrost operation or at the time of the defrost operation and the first preliminary operation. Since the water vapor generated during the defrosting operation is not sent into the container main body 2, the load B in the container main body 2 can be prevented from getting wet.
Further, since the damper device 8 is provided not in the container main body 2 but in the refrigeration apparatus 1, the configuration of the container main body 2 is simplified and the manufacture thereof is facilitated, and the existing container main body 2 is also provided with a damper device. The refrigeration apparatus 1 can be installed without performing the construction for installing 8.

Here, in the present embodiment, the example in which the refrigeration apparatus 1 is configured to perform the first preliminary operation and the second preliminary operation after the defrost operation has been described, but is not limited thereto, and only the first preliminary operation is performed. It is good also as a structure.
Moreover, although the example which closed the damper apparatus 8 at the time of 1st preliminary operation was shown in this embodiment, it is not restricted to this, You may open the damper apparatus 8 at the time of 1st preliminary operation.

It is a longitudinal cross-sectional view which shows the structure of the freezing apparatus concerning one Embodiment of this invention. It is an enlarged view of FIG. It is a flowchart which shows operation | movement of the freezing apparatus concerning one Embodiment of this invention. It is a flowchart which shows operation | movement of the freezing apparatus concerning one Embodiment of this invention.

Explanation of symbols

1 Refrigeration equipment (refrigeration cycle equipment)
2 Container body (freezer compartment)
3 Refrigerant Circuit 6 Casing 6f Discharge Port 7 Refrigerant Circuit 8 Damper Device 11 Evaporator 16 Blower Device for Evaporator 17 Heater 18 Control Device

Claims (5)

Using an evaporator provided on the refrigerant circuit forming the refrigeration cycle, heat exchange is performed between the refrigerant circulating in the refrigerant circuit and the atmosphere in the refrigerator compartment, or between the refrigerant and the atmosphere in the freezer compartment. A refrigerating cycle device for performing cooling of the refrigerating room atmosphere or the refrigerating room atmosphere,
A casing in which a discharge port is provided above and the evaporator is housed;
A blower that takes in the refrigerated room atmosphere or the freezer room atmosphere into the casing and delivers the air toward the outlet;
A heater for heating the evaporator during defrost operation;
A control device for controlling the operation of the blower,
The control device stops the blower during the defrost operation,
After the defrosting operation is finished, after performing the first preliminary operation of switching the blowing direction of the blower device in the reverse direction and blowing air,
The refrigeration cycle apparatus is configured to perform normal operation by switching the blowing direction of the blowing device to the positive direction again.   After the first preliminary operation is completed, the control device switches the air blowing direction of the air blowing device to a positive direction, and performs air blowing in a state where the air blowing amount of the air blowing device is reduced as compared with the normal operation. The refrigeration cycle apparatus according to claim 1, wherein the normal operation is performed after two preliminary operations are performed.   The refrigeration cycle apparatus according to claim 1, wherein the casing is provided with a damper device that regulates ventilation between the refrigerator compartment and the freezer compartment through the discharge port. An evaporator provided on a refrigerant circuit forming a refrigeration cycle, a casing in which the evaporator is housed and a discharge port is provided above, and a chilled room atmosphere or a freezer room atmosphere is taken into the casing. An air blower that delivers the air to the discharge port; and a heater that heats the evaporator and performs defrosting, between the refrigerant circulating in the refrigerant circuit and the atmosphere in the refrigerator compartment, or between the refrigerant and the freezer compartment An operation method of a refrigeration cycle apparatus that performs heat exchange with an atmosphere to cool the refrigerated room atmosphere or the freezer room atmosphere,
During the defrost operation, the blower is stopped,
After the defrosting operation is completed, a first preliminary operation is performed in which the air blowing direction of the blower is switched to the opposite direction to blow air,
A method for operating a refrigeration cycle apparatus, wherein normal operation is performed by switching the blowing direction of the blowing device to a positive direction again.   After the first preliminary operation is finished, after the air blowing direction of the air blower is switched to the positive direction, a second preliminary operation is performed in which air is blown in a state where the air blowing amount of the air blower is reduced as compared with the normal operation. 5. The operation method of the refrigeration cycle apparatus according to claim 4, wherein the normal operation is performed later.

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