JP2009068814A - Refrigerating device for refrigerator car - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the occurrence of water splashing when defrosting operation terminates and refrigerating operation restarts. <P>SOLUTION: A downstream side damper 33 for opening and closing an air passage 300 is disposed at the downstream side of an evaporator 25. After the defrosting operation terminates and before the refrigerating operation starts, a blower 31 is operated in a state of the air passage 300 being closed by the downstream side damper 33. Thereby, condensed water separated from the evaporator 25 is discharged to the outside of a refrigerator 10 via a drain port after dropping in a drain pan 35. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a refrigeration apparatus for a refrigerator car that cools the inside of a freezer.

In order to cool the evaporator whose temperature has risen during the defrosting operation, the conventional refrigeration apparatus for a refrigerator car operates the compressor and stops the blower that blows air to the evaporator side for a certain period of time after the defrosting operation is completed. The evaporator precooling operation is performed (see, for example, Patent Document 1).
JP-A-10-160298

  However, the conventional refrigeration apparatus for a freezer has a problem that the condensed water adhering to the evaporator during the defrosting operation is re-frozen by the pre-cooling operation, and the wind speed and the cooling capacity are reduced due to the blockage between the fins of the evaporator. Has occurred.

  Further, when the fin pitch of the evaporator is narrowed for miniaturization, the wind speed between the fins increases, so that the so-called water splash that the condensed water adhering to the evaporator is blown to the inside of the freezer is likely to occur. In particular, since a large amount of condensed water adheres to the evaporator at the end of the defrosting operation, water jumps easily when the defrosting operation is completed and the refrigeration operation is resumed.

  In view of the above points, the present invention is intended to prevent the occurrence of blockage between the fins of the evaporator due to water splashing or refreezing of condensed water when the defrosting operation is completed and the refrigeration operation is resumed. Objective.

  The present invention relates to a freezing vehicle refrigeration apparatus that performs a refrigeration operation for cooling the inside of the freezer (10) and a defrosting operation for removing frost attached to the evaporator (25). The downstream damper (33) to be opened and closed is disposed downstream of the evaporator (25), and the air passage (300) is closed by the downstream damper (33) after the defrosting operation is completed and before the refrigerating operation is resumed. And operating the blower (31).

  If it does in this way, since blowing air at the time of operating a blower (31) after completion of defrosting operation is controlled from flowing into a freezer (10) by valve closing operation of a downstream damper (33), The condensed water separated from the evaporator (25) by the air blow after the defrosting operation is dropped to the drain pan (35) and then discharged out of the freezer (10) through the drain port. Accordingly, it is possible to prevent water splashing when the refrigeration operation is resumed, and to prevent blockage between the fins of the evaporator due to refreezing of the condensed water.

  In this case, the upstream damper (32) that opens and closes the air passage (300) is arranged upstream of the evaporator (25), and the air passage is formed by the upstream damper (32) and the downstream damper (33) during the defrosting operation. If (300) is closed, heat exchange between the low-temperature air in the air passage (300) and the high-temperature refrigerant gas passing through the evaporator (25) is reduced, so that evaporation during the defrosting operation is performed. It is possible to shorten the defrosting time by accelerating the temperature rise of the container (25), and to reduce the heat radiation into the freezer (10) and to suppress the temperature rise in the cabinet.

  Further, when the air passage (300) is closed by the upstream damper (32) and the downstream damper (33) during the freezing operation and the door of the freezer (10) is open, the freezing operation can be performed. When the door of the freezer (10) is opened, heat exchange with the outside air can be suppressed and condensation on the evaporator (25) can be suppressed.

  Further, if the blower (31) is stopped during the freezing operation and the door of the freezer (10) is open, the outside air is opened when the door of the freezer (10) is opened during the freezing operation. And the dew condensation on the evaporator (25) can be further suppressed.

  In addition, the code | symbol in the bracket | parenthesis of each means described in a claim and this column shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
A first embodiment of the present invention will be described. FIG. 1 is a diagram showing a vehicle equipped with a refrigeration vehicle refrigeration apparatus according to the first embodiment, and FIG. 2 is a diagram showing a configuration of a refrigeration cycle apparatus in the refrigeration apparatus of FIG.

  As shown in FIGS. 1 and 2, the vehicle is provided with a freezer 10 for storing a load such as frozen food. A door 12 that opens and closes a rear opening 11 for loading or unloading a load is provided at a rear portion of the freezer 10. Further, the rear opening 11 is provided with a door switch 13 that detects opening and closing of the door 12.

  Further, the vehicle is provided with a refrigeration cycle apparatus R that cools the inside of the freezer 10. The refrigeration cycle apparatus R includes a compressor 20, an oil separator 21, a condenser 22, a liquid receiver 23, an expansion valve 24, an evaporator 25, and a gas-liquid separator 26.

  The compressor 20 is driven by a traveling engine (not shown) via the electromagnetic clutch 200 to suck, compress, and discharge the refrigerant. The oil separator 21 separates oil in the refrigerant discharged from the compressor 20. The condenser 22 cools the high-temperature / high-pressure refrigerant discharged from the compressor 20 with outside air. The liquid receiver 23 separates the refrigerant flowing out of the condenser 22 into a liquid phase refrigerant and a gas phase refrigerant. The expansion valve 24 depressurizes the liquid-phase refrigerant that passes through the liquid receiver 23. The evaporator 25 evaporates the refrigerant from the expansion valve 24 and cools the air in the freezer 10. The gas-liquid separator 26 separates the refrigerant flowing out of the evaporator 25 into a liquid phase refrigerant and a gas phase refrigerant, and returns the gas phase refrigerant to the suction side of the compressor 20.

  3 is a view of the vicinity of the evaporator 25 during the refrigeration operation, and FIG. 4 is a view of the vicinity of the evaporator 25 when the door 12 is open or after the defrosting operation.

  As shown in FIGS. 3 and 4, a resin case 30 that forms an air passage 300 therein is disposed at an upper position in the freezer 10. A blower 31 that draws air from the inside of the freezer 10 and generates an air flow is disposed on the most upstream side of the air passage 300. The blower 31 includes an electric motor and an impeller that is driven by the electric motor to generate an air flow.

  An evaporator 25 is arranged on the downstream side of the blower 31 in the air passage 300. The evaporator 25 is a so-called plate fin type evaporator in which a large number of metal pipes through which a refrigerant flows are penetrated and joined to a metal thin plate. Here, the blower 31 and the evaporator 25 are arranged side by side in the horizontal direction in order to make the unit in the freezer whose main components are the blower 31 and the evaporator 25 thin. Further, an evaporator upper gap 301 through which air can flow is provided between the upper surface of the evaporator 25 and the upper inner wall surface of the freezer 10.

  An upstream damper 32 that opens and closes the air passage 300 is disposed on the upstream side of the evaporator 25 in the air passage 300, more specifically, at a position close to the air inflow surface 250 of the evaporator 25. In a state where the upstream damper 32 closes the air passage 300, the air inflow surface 250 of the evaporator 25 is covered to prevent the inflow of air from the air inflow surface 250 into the evaporator 25, and the upstream side A gap is formed between the damper 32 and the upper inner wall surface of the freezer 10, and air can flow from the gap to the evaporator upper gap 301. The upstream damper 32 is rotatably attached to the case 30 and is driven by an electric motor (not shown).

  A downstream damper 33 that opens and closes the air passage 300 is disposed downstream of the evaporator 25 in the air passage 300, more specifically, at a position close to the air outflow surface 251 of the evaporator 25. In the state where the downstream damper 33 closes the air passage 300, the blowing of air from the evaporator 25 into the freezer 10 is prevented. The downstream damper 33 is rotatably assembled to the case 30 and is driven by an electric motor (not shown).

  An evaporator outlet temperature sensor 34 that detects the outlet refrigerant temperature of the evaporator 25 is attached to the air outflow surface 251 of the evaporator 25.

  A drain pan 35 that receives the condensed water of the evaporator 25 is disposed at a lower position of the evaporator 25, and the condensed water that has fallen on the drain pan 35 is outside the freezer 10 (ie, through a drain port 36 and a drain hose (not shown)). It is discharged to the outside of the car. The drain pan 35 and the drain port 36 are formed integrally with the case 30.

  As shown in FIG. 1, the vehicle is provided with a control device 40, and the control device 40 includes a microcomputer, a memory, a peripheral circuit, and the like. The control device 40 controls the electromagnetic clutch 200, the blower 31, the upstream damper 32, and the downstream damper 33 based on the output signal of the door switch 13 and the output signal of the evaporator outlet temperature sensor 34.

  FIG. 5 is a flowchart of a program that is read and executed by the CPU of the control device 40. The operation of the apparatus according to the present embodiment having the above configuration will be described below based on the flowchart of FIG.

  First, when an ignition switch (not shown) is turned on, the air temperature in the freezer 10 is maintained at a target temperature (for example, −10 ° C. to −20 ° C.) in step S100 as the freezing operation control means. Then, a well-known freezing operation is started. Specifically, the electromagnetic clutch 200 is energized to drive the compressor 20 by the traveling engine, and the fan 31 is operated. At this time, as shown in FIG. 3, the upstream damper 32 and the downstream damper 33 fully open the air passage 300. In step S100, the first timer is started to measure the time during which the refrigeration operation is continued.

  Next, in step S110 as a door determination means, the open / closed state of the door 12 of the freezer 10 is determined based on the detection signal of the door switch 13. When the door 12 is opened during the refrigeration operation (YES in step S110), in step S120 as the dew condensation suppressing means, the blower 31 is stopped while the operation of the compressor 20 is continued, and further shown in FIG. Thus, the air passage 300 is closed by the upstream damper 32 and the downstream damper 33. By this dew condensation suppression operation, heat exchange between the refrigerant and the outside air is suppressed, and dew condensation on the evaporator 25 is suppressed.

  Next, when the door 12 is closed (YES in step S130), the operation of the blower 31 is started, and the upstream damper 32 and the downstream damper 33 fully open the air passage 300 as shown in FIG. The refrigeration operation is restored (step S140).

  Then, after the execution of step S140 or when a negative determination is made in step S110, the process proceeds to step S150. In step S150, it is determined whether or not defrosting is performed. Specifically, if the time during which the refrigeration operation is continuously executed (that is, the time of the first timer started in step S100) is equal to or longer than a first set time (for example, 1 hour) (step S150) YES), the process proceeds to step S160. The first set time is stored in the memory of the control device 40.

  In step S160 as the defrosting operation control means, the first timer is reset, and the blower 31 is stopped and the defrosting operation is performed while the operation of the compressor 20 is continued. And the frost adhering to the evaporator 25 is thawed and removed by the high-temperature refrigerant gas sent from the compressor 20.

  In step S160, the air passage 300 is closed by the upstream damper 32 and the downstream damper 33. As a result, heat exchange between the low-temperature air in the air passage 300 and the high-temperature refrigerant gas passing through the evaporator 25 is reduced, and the temperature rise of the evaporator 25 during the defrosting operation is accelerated to reduce the defrosting time. While shortening, the heat dissipation in the freezer 10 is reduced and the temperature rise in the refrigerator is suppressed.

  When the outlet refrigerant temperature of the evaporator 25 detected by the evaporator outlet temperature sensor 34 is equal to or higher than the set temperature (YES in step S170), the process proceeds to step S180 as the condensed water discharge control means.

  In step S180, the defrosting operation is terminated and the condensed water discharge operation is performed. Specifically, the operation of the compressor 20 continues, and the operation of the blower 31 is started while the air passage 300 is closed by the upstream damper 32 and the downstream damper 33.

  At this time, as shown in FIG. 4, the upstream damper 32 prevents air from flowing from the air inflow surface 250 into the evaporator 25, and the downstream damper 33 blocks air from the evaporator 25 into the freezer 10. Therefore, the air sent out from the blower 31 flows into the evaporator upper gap 301 through the gap between the upstream damper 32 and the upper inner wall surface of the freezer 10, and moves from the top to the bottom in the evaporator 25. It flows toward. The condensed water generated during the defrosting operation and adhering to the surface of the evaporator 25 is dropped to the drain pan 35 by the air flowing from the top to the bottom in the evaporator 25, via the drain port 36 and the drain hose. It is discharged out of the freezer 10. Therefore, it is possible to prevent water splashing when the refrigeration operation is resumed, and to prevent blockage between the fins of the evaporator 25 due to refreezing of condensed water.

  In Step S180, the second timer is started to measure the time during which the condensed water discharge operation is continuously executed.

  If the time during which the condensed water discharge operation is continuously executed (that is, the time of the second timer started in step S180) is equal to or longer than the second set time (for example, 1 minute) (YES in step S190). ), Go to step S200. The second set time is stored in the memory of the control device 40.

  In this step S200, the second timer is reset, and the upstream damper 32 and the downstream damper 33 fully open the air passage 300 as shown in FIG. 3 to return to the normal refrigeration operation. At this time, the downstream damper 33 is controlled to be gradually opened to prevent water jumping.

(Second Embodiment)
A second embodiment of the present invention will be described. FIG. 6 is a view of the vicinity of the evaporator 25 in the refrigeration apparatus according to the second embodiment. In addition, the same code | symbol is attached | subjected to the same or equivalent part as 1st Embodiment, and the description is abbreviate | omitted.

  In the first embodiment, the air passage 300 is closed by the upstream damper 32 during the condensate discharge operation (that is, the entire air inflow surface 250 of the evaporator 25 is covered). Thus, during the condensed water discharge operation, the upstream damper 32 slightly opens the air passage 300 (that is, opens a part of the air inflow surface 250 of the evaporator 25).

  According to this, the air sent out from the blower 31 flows into the evaporator upper gap 301 through the gap between the upstream damper 32 and the upper inner wall surface of the freezer 10 and flows in the evaporator 25 from top to bottom. Later, the air flow returns to the air passage 300 upstream of the upstream damper 32 from the open portion of the air inflow surface 250. The condensed water adhering to the surface of the evaporator 25 is dropped to the drain pan 35 by the air flowing from the top to the bottom in the evaporator 25 and discharged outside the freezer 10 through the drain port 36 and the drain hose. . Therefore, it is possible to prevent water splashing when the refrigeration operation is resumed, and to prevent blockage between the fins of the evaporator 25 due to refreezing of condensed water.

(Third embodiment)
A third embodiment of the present invention will be described. FIG. 7 is a view of the vicinity of the evaporator 25 in the refrigeration apparatus according to the third embodiment. In addition, the same code | symbol is attached | subjected to the same or equivalent part as 1st Embodiment, and the description is abbreviate | omitted.

  In this embodiment, as shown in FIG. 7, the upper surface of the evaporator 25 is brought into close contact with the upper inner wall surface of the freezer 10 to eliminate the evaporator upper gap 301 in the first embodiment, and the upstream in the first embodiment. The side damper 32 is abolished.

  According to this, since the downstream damper 33 closes the air passage 300 during the condensed water discharge operation, the air sent from the blower 31 passes through the evaporator 25 and then passes through the drain port 36 and the drain hose. It is discharged out of the freezer 10. Similarly, since the condensed water separated from the evaporator 25 by the air passing through the evaporator 25 is prevented from being blown out into the freezer 10 by the downstream damper 33, the freezer is provided via the drain port 36 and the drain hose. 10 is discharged outside. Therefore, it is possible to prevent water splashing when the refrigeration operation is resumed, and to prevent blockage between the fins of the evaporator 25 due to refreezing of condensed water.

(Other embodiments)
In each of the above embodiments, the outlet refrigerant temperature of the evaporator 25 is detected by the evaporator outlet temperature sensor 34, but the temperature of the air blown from the evaporator 25 may be detected.

1 is a diagram illustrating a vehicle equipped with a refrigeration apparatus for a refrigeration vehicle according to a first embodiment of the present invention. It is a figure which shows the structure of the refrigeration cycle apparatus in the refrigeration apparatus of FIG. It is a figure of the evaporator 25 vicinity at the time of the freezing operation of the freezing apparatus of FIG. It is the figure of the evaporator 25 vicinity when the door 12 of the freezing apparatus of FIG. 1 is open, or after a defrost operation. FIG. 1 is a flowchart of a program executed by the control device 40. It is a figure of the evaporator 25 vicinity in the freezing apparatus which concerns on 2nd Embodiment of this invention. It is a figure of the evaporator 25 vicinity in the freezing apparatus which concerns on 3rd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Freezer, 20 ... Compressor, 25 ... Evaporator, 30 ... Case, 31 ... Blower, 33 ... Downstream damper, 35 ... Drain pan, 300 ... Air passage.

Claims (5)

A compressor (20) for compressing and discharging the refrigerant;
A case (30) disposed in a freezer (10) mounted on a vehicle and forming an air passage (300) therein;
A blower (31) disposed in the air passage (300) and sucking air from within the freezer (10) to generate an air flow;
An evaporator (25) disposed on the downstream side of the blower (31) in the air passage (300) to cool the air by exchanging heat between the air and the refrigerant;
A drain pan (35) formed in the case (30) and receiving the condensed water of the evaporator (25);
Refrigeration operation control means (S100) for controlling the operation of the compressor (20) and the blower (31) to perform a refrigeration operation for cooling the inside of the freezer (10);
Refrigeration provided with a defrosting operation control means (S160) for controlling the operation of the compressor (20) and the blower (31) and performing a defrosting operation for removing frost attached to the evaporator (25). In car refrigeration equipment,
A downstream damper (33) disposed downstream of the evaporator (25) in the air passage (300) and opening and closing the air passage (300);
Condensed water discharge control means (S180) for operating the blower (31) with the air damper (300) closed by the downstream damper (33) after the defrosting operation is completed and before the refrigerating operation is resumed. A refrigeration apparatus for a freezing vehicle comprising: An upstream damper (32) disposed on the upstream side of the evaporator (25) in the air passage (300) and opening and closing the air passage (300);
The defrosting operation control means (S160) closes the air passage (300) by the upstream damper (32) and the downstream damper (33) during the defrosting operation. The refrigeration apparatus for a refrigerator car as described. An upstream damper (32) disposed upstream of the evaporator (25) in the air passage (300) and opening and closing the air passage (300);
Door determination means (S110) for determining the open / closed state of the door of the freezer (10);
When the door of the freezer (10) is determined to be open by the door determination means (S110) during the refrigeration operation, the air is discharged by the upstream damper (32) and the downstream damper (33). The refrigeration apparatus for a refrigerator car according to claim 1, further comprising a dew condensation suppressing means (S120) for closing the passage (300). The dew condensation suppression means (S120) stops the blower (31) when the door of the freezer (10) is determined to be in an open state by the door determination means (S110) during the refrigeration operation. The refrigeration apparatus for a refrigerator car according to claim 3. The refrigeration apparatus for a refrigerator car according to any one of claims 1 to 4, wherein the evaporator (25) is a plate fin type evaporator.

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