JP2015138313A - Automatic vending machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic vending machine capable of preventing oil shortage in a compressor even when a merchandise storage chamber set in a heated state exists.SOLUTION: An automatic vending machine 100 includes: a first cooling/heating chamber 2 and a second cooling/heating chamber 3 for storing merchandise by switching to cooling or heating; and a cooling dedicated chamber 4 for storing the cooled merchandise, therein first to third evaporators 19, 20 and 21 in a refrigeration cycle 5 are respectively disposed in those first cooling/heating chamber 2, second cooling/heating chamber 3 and cooling dedicated chamber 4, and first to second electric heaters 34 and 35 are disposed in the first cooling/heating chamber 2 and the second cooling/heating chamber 3. The automatic vending machine 100 includes a control unit for, when the first cooling/heating chamber 2 is set in a heated state, allowing coolant to periodically circulate in the first evaporator 19 of the first cooling/heating chamber 2 set in the heated state to return oil accumulated in the first evaporator 19 to a compressor 7.

Description

  The present invention relates to a vending machine that sells products such as canned beverages cooled or heated using a refrigeration cycle.

  In general, there is a vending machine equipped with a hot / cold switching product storage room for storing canned beverages or the like by switching to cooling or heating, and a cold dedicated product storage room for cooling and storing the products. (For example, refer to Patent Document 1). In this type of vending machine, each product storage room is equipped with an evaporator for the refrigeration cycle so that the room (product) can be cooled, and a heating unit such as a heater is placed in the hot / cold switching product storage room. And the structure which can heat the room (product) is adopted.

JP 2009-251857 A

By the way, in the structure which cools goods using a refrigerating cycle, since the differential pressure between a compressor and an evaporator becomes large, when the compressor stops, oil mixed with refrigerant flows out from the compressor. As a result, this oil tends to accumulate in the evaporator.
In particular, in a hot / cold switching product storage room, during the period when the product storage room is heated (for example, in winter), normal refrigerant does not flow through the evaporator, so oil gradually accumulates in the evaporator and is compressed. The problem of running out of oil in the plane can occur.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a vending machine capable of preventing oil shortage in a compressor even when there is a product storage room set in a warmed state. .

  In order to solve the above-described conventional problems, the present invention includes a hot / cold switching product storage room and a cold dedicated product storage room, and arranges an evaporator of a refrigeration cycle for cooling the interior of each of the product storage rooms. In the vending machine in which the hot / cold switching product storage room is provided with a heating unit for heating the room, when the hot / cold switching product storage room is set to warm, the hot / cold switching product storage is stored. The evaporator of the chamber is provided with an oil return control unit that causes the refrigerant to circulate regularly or irregularly to return the oil accumulated in the evaporator to the compressor.

  In this configuration, the oil return control unit may stop the operation of the blower fan disposed close to the evaporator while circulating the refrigerant to the evaporator of the hot / cold switching product storage chamber. . The oil return control unit may cause the refrigerant to flow through the evaporator of the hot / cold switching product storage chamber on condition that the defrosting of the evaporator of the cold dedicated product storage chamber is completed.

  Further, when there are a plurality of hot / cold switching product storage chambers, the oil return control unit may sequentially distribute the refrigerant to each evaporator in the hot / cold switching product storage chambers. In addition, after a predetermined time has elapsed since the start of the flow of the refrigerant to the evaporator of the hot / cold switching product storage chamber, the refrigerant is not supplied to the evaporator of the hot / cold switching product storage chamber while continuing to operate the compressor. You may transfer to the normal operation | movement which distribute | circulates a refrigerant | coolant to the evaporator of the said cold exclusive goods storage chamber while interrupting distribution | circulation and operating the said heating part.

  According to the present invention, when the hot / cold switching product storage chamber is in a heated state, the refrigerant is circulated through the evaporator of the hot / cold switching product storage chamber, and the oil accumulated in the evaporator is compressed. Since the oil return control unit for returning to the above is provided, it is possible to eliminate a situation in which a large amount of oil is accumulated in the evaporator of the hot / cold switching product storage chamber, and it is possible to prevent oil shortage in the compressor.

It is a refrigerant circuit figure of the vending machine concerning this embodiment. It is a functional block diagram of the controller of a vending machine. It is a flowchart which shows the oil return control procedure of a vending machine. It is a refrigerant circuit diagram of the vending machine concerning another embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.
FIG. 1 is a refrigerant circuit diagram of a vending machine according to the present embodiment.
As shown in FIG. 1, the vending machine 100 includes a product storage 1 that stores products such as canned beverages, and a machine room (not shown) that is disposed below the product storage 1. The product storage 1 is divided into three sections, a first cooling greenhouse 2 for cooling or heating the stored product, a second cooling greenhouse 3 (hot / cold switching product storage room), and cooling the stored product. And a dedicated cooling room 4 (cold dedicated product storage room). In each room, a product storage shelf (not shown) is suspended at the top, and the product is stored inside.

The vending machine 100 includes a refrigeration cycle 5 in which a carbon dioxide (CO ₂ ) refrigerant circulates. The refrigeration cycle 5 includes a compressor 7 that compresses the refrigerant, a gas cooler 9 as a radiator, a strainer 11, and can be opened and closed. First to third solenoid valves (opening / closing means) 13, 14, 15; first to third capillary tubes (decompression means) 16, 17, 18; first to third evaporators 19, 20, 21; An internal heat exchanger 22 is provided.
The compressor 7 is a rotary compressor that can compress the refrigerant to the supercritical pressure on the high pressure side of the refrigeration cycle 5, compresses the low-pressure refrigerant sucked from the refrigerant suction pipe 23, and discharges the high-temperature and high-pressure refrigerant to the refrigerant discharge pipe 24. Is done.
The refrigerant discharge pipe 24 is connected to the inlet side of the gas cooler 9, and the outlet side pipe 26 having the strainer 11 is connected to the outlet side of the gas cooler 9. Between the outlet side pipe 26 and the refrigerant suction pipe 23, first to third evaporators 19, 20, and 21 are connected in parallel to each other. The first to third evaporators 19, 20, and 21 are disposed in the first cooling chamber 2, the second cooling chamber 3, and the cooling chamber 4, respectively. Between the strainer 11 and the first to third evaporators 19, 20, 21, the first to third solenoid valves 13, 14, 15 and the first to third capillary tubes 16 are arranged along the refrigerant flow direction. , 17 and 18 are provided in series, respectively.
The refrigerant suction pipe 23 is provided with a check valve 25 for preventing the refrigerant from flowing backward.

  The internal heat exchanger 22 is disposed between the refrigerant suction pipe 23 and the outlet side pipe 26 of the gas cooler 9, and the high-pressure refrigerant cooled by the gas cooler 9 and the low-pressure evaporated by the evaporators 19, 20, and 21, respectively. Heat exchange is performed with the gas refrigerant. In the present embodiment, by providing the internal heat exchanger 22, the refrigerant that has passed through the gas cooler 9 can be further cooled to increase the cooling capacity.

The gas cooler 9 is provided with a gas cooler blower fan 27 that blows air toward the gas cooler 9. Similarly, the first to third evaporators 19, 20, and 21 have first to third evaporator fans 28, 29, and 30 that blow air toward the first to third evaporators 19, 20, and 21, respectively. And the 1st-3rd evaporator temperature detection sensors 31, 32, and 33 which detect the temperature of the 1st-3rd evaporators 19, 20, and 21 are arrange | positioned.
The first and second cooling greenhouses 2 and 3 are provided with first and second electric heaters (heating units) 34 and 35 for heating the room, respectively. Further, the first cooling greenhouse 2, the second cooling greenhouse 3, and the cooling exclusive chamber 4 are provided with first to third indoor temperature detection sensors 36, 37, and 38 for detecting the temperature of each room.
Each part of the vending machine 100 is operation-controlled based on the controller 40, cools the product stored in the cooling exclusive chamber 4 to an appropriate temperature, and, according to the setting of the user, the first cooling greenhouse 2, 2 Cool or warm the product stored in the cooling greenhouse 3 to an appropriate temperature.

The operation of the vending machine 100 configured as described above will be described.
First, when all the chambers are set to be cooled, the compressors 7 are started by opening all the first to third electromagnetic valves 13, 14, 15. The first to third solenoid valves 13, 14, 15 may be opened at the same time, or may be opened in order at intervals. The refrigerant discharged from the compressor 7 flows through the refrigerant discharge pipe 24 and flows into the gas cooler 9 to be cooled. The cooled liquid refrigerant is distributed into three, passes through the first to third electromagnetic valves 13, 14, 15, and is depressurized by the first to third capillary tubes 16, 17, 18. The third evaporators 19, 20, and 21 evaporate and cool the surrounding air. The evaporated and evaporated refrigerant joins again and returns to the compressor 7 through the refrigerant suction pipe 23.

Next, when the first cooling greenhouse 2 is heated and the second cooling greenhouse 3 and the cooling exclusive chamber 4 are set to cool, the first electromagnetic valve 13 is closed, the second electromagnetic valve 14 and the second 3 Open the solenoid valve 15 and start the compressor 7. In this case, since the first electromagnetic valve 13 is closed, the liquid refrigerant cooled by the gas cooler 9 does not flow through the first evaporator 19.
On the other hand, the first electric heater 34 is energized and heating is performed until the first cooling greenhouse 2 reaches a predetermined temperature. The 1st evaporator ventilation fan 28 is drive | operated, and the heat heated with the 1st electric heater 34 prevents the temperature nonuniformity in the 1st cooling heating greenhouse 2.
About the cooling operation of the 2nd cooling greenhouse 3 and the cooling exclusive room 4, since it is the same as that of the case where all above-mentioned rooms are cooled, description is abbreviate | omitted.
When the second cooling greenhouse 3 is heated and the first cooling greenhouse 2 and the cooling exclusive chamber 4 are set to be cooled, the second electromagnetic valve 14 is closed, the first electromagnetic valve 13 and The third electromagnetic valve 15 is opened and the compressor 7 is started. In this case, the second electric heater 35 is energized and heating is performed until the second cooling greenhouse 3 reaches a predetermined temperature. Further, the second evaporator blower fan 29 is operated. Furthermore, when the first cooling greenhouse 2 and the second cooling greenhouse 3 are heated and the cooling exclusive chamber 4 is set to cool, the first electromagnetic valve 13 and the second electromagnetic valve 14 are closed, The third electromagnetic valve 15 is opened and the compressor 7 is started. In this case, the first electric heater 34 and the second electric heater 35 are energized and heating is performed until the first cooling greenhouse 2 and the second cooling greenhouse 3 reach predetermined temperatures, respectively. The first evaporator blower fan 28 and the second evaporator blower fan 29 are operated.

FIG. 2 is a control block diagram of the controller 40.
The controller 40 controls the overall operation of the vending machine 100, and based on instructions from the control unit 41, the compressor 7, the first electric heaters 34 and 35, and the first to third evaporator blower fans 28. , 29, 30, compressor frequency control unit 42, heater control unit 43, evaporator blower fan rotation speed control unit 44, solenoid valve control unit 45 for controlling the operations of the first to third electromagnetic valves 13, 14, 15 respectively. With.
The control unit 41 includes a clock unit 47 that measures the current time, and a schedule management unit 48 that manages the defrost of the evaporator in the chamber that is set to be cooled and the schedule of the oil return operation described later.
Further, the controller 40 includes a cooling / heating setting unit 46 provided in the operation unit of the vending machine 100, first to third evaporator temperature detection sensors 31, 32, 33, and first to third indoor temperature detection sensors. 36, 37, and 38 are connected. The cooling / warming setting unit 46 sets the cooling or heating operation of the first cooling / heating chamber 2 and the second cooling / heating chamber 3 according to the user's operation, and the control unit 41 cools these rooms. Based on the setting or heating setting, the opening / closing of each solenoid valve, the operation of each heater, the rotational speed of the compressor, and the like are controlled.

By the way, in the structure which cools goods using a refrigerating cycle, the differential pressure | voltage between the compressor 7 and the 1st-3rd evaporators 19-21 becomes large. In particular, in this embodiment, since the carbon dioxide refrigerant is used, the discharge pressure of the compressor 7 becomes higher than that of the HFC refrigerant, and the differential pressure tends to be further increased.
When the operation of the compressor 7 is stopped, a situation may occur in which oil (lubricating oil) in the compressor 7 flows backward to the first to third evaporators 19 to 21 through the refrigerant suction pipe 23 based on the above-described differential pressure. . Since the refrigerant flows into the evaporator in the product storage room set to be cooled by the next start of the compressor 7, the oil accumulated in the evaporator by the flow of the refrigerant can be returned to the compressor 7. . On the other hand, no refrigerant flows through the warmer-set evaporator in the product storage room during the warm-up period (for example, during winter). For this reason, every time the operation of the compressor stops, the oil gradually accumulates in the evaporator, and eventually there may be a problem that the oil in the compressor becomes insufficient.
For this reason, the vending machine 100 according to the present configuration executes oil return control for returning the oil accumulated in the evaporator in the warmed product storage chamber to the compressor, and the control unit 41 of the controller 40 performs the oil return control. Functions as a return control unit.

Next, the procedure of oil return control will be described.
FIG. 3 is a flowchart showing an oil return control procedure.
The control unit 41 determines whether or not there is a product storage room that is heated (step S1). If there is no product storage room (step S1; No), the process ends. On the other hand, when there is a product storage room (for example, the first cooling greenhouse 2 and the second cooling greenhouse 3) that are heated (step S1; Yes), the control unit 41 sets the product storage room ( Defrosting of the evaporator (third evaporator 21) in the cooling only chamber 4) is performed (step S2).
Specifically, the defrosting is executed by the control unit 41 based on a schedule stored in the schedule management unit 48 in advance. During defrosting, the cooling operation in the product storage room is stopped, so that the sale starts at midnight (for example, at 2:00 AM) when there is little sales in order to suppress the influence on the product stored in the room as much as possible.

  The control unit 41 stops the operation of the compressor 7 through the compressor frequency control unit 42, and controls the rotation speed of the third evaporator blower fan 30 in the cooling exclusive chamber 4 through the evaporator blower fan rotation speed control unit 44. The maximum number of revolutions (full speed) is set (step S3). Due to the wind speed of the third evaporator blower fan 30 operated at the maximum number of rotations (full speed), frost attached to the third evaporator 21 in the cooling only chamber 4 is melted and defrosting is performed.

Subsequently, the control unit 41 monitors the detected temperature of the third evaporator detected temperature sensor 33 and determines whether or not the detected temperature TH is equal to or higher than a predetermined temperature (for example, 7 ° C.) (step S4). This predetermined temperature is generally a temperature at which it is assumed that the evaporator is no longer frosted, and it is considered that the defrost has been completed when the predetermined temperature is exceeded.
In this determination, when the detected temperature TH is not equal to or higher than a predetermined temperature (for example, 7 ° C.) (step S4; No), the control unit 41 returns the process to step S3 and sets the detected temperature TH to be equal to or higher than the predetermined temperature. Repeat the process until On the other hand, the control part 41 complete | finishes defrost, when the detection temperature TH is more than predetermined temperature (for example, 7 degreeC) (step S4; Yes) (step S5). If there are two or more commodity storage rooms that are set to be cooled, defrosting in each room may be performed in parallel.

Subsequently, the control unit 41 operates to return the oil accumulated in the evaporator of the warmed product storage chamber to the compressor on the condition that the defrosting of the cooler of the commercial product chamber is completed. I do. In general, defrosting is performed regularly at midnight when there is little merchandise sales. Therefore, the temperature of the merchandise stored in the merchandise storage chamber of the vending machine 100 is obtained by performing oil return following the defrosting. The fluctuation can be suppressed as much as possible. Further, by returning the oil following the defrost, the oil that has flowed back to the first and second evaporators 19 and 20 from the compressor 7 stopped due to the defrost is also returned to the compressor 7. It becomes possible.
Specifically, the control unit 41 passes through the heater control unit 43 to the first electric heater 34 and the second electric heater 35 disposed in the first cooling greenhouse 2 and the second cooling greenhouse 3 which are set to be heated. And the rotation speeds of the first evaporator blower fan 28 and the second evaporator blower fan 29 are set to the maximum rotation speed (full speed) through the evaporator blower fan rotation speed control unit 44 (step S6). ).
By operating the first evaporator blower fan 28 and the second evaporator blower fan 29 at the maximum number of revolutions, the first electric heater 34 and the second electric heater 35 that have been de-energized are rapidly cooled. And it is possible to prevent the heater from being damaged due to heat accumulation.

Next, the control unit 41 determines whether or not there are two commodity storage rooms that are set to be heated (step S8). Specifically, the control unit 41 acquires the setting state from the cooling / warming setting unit 46. In this determination, when there are two product storage chambers that have been heated (step S8; Yes), the control unit 41 first opens the first electromagnetic valve 13 of the first cooling greenhouse 2, The second electromagnetic valve 14 of the second cooling greenhouse 3 and the third electromagnetic valve 15 of the cooling chamber 4 are closed, and the operation of the compressor 7 is started (step S9).
In this case, the compressor 7 gradually increases the operating frequency to the target frequency after being started at a predetermined starting frequency based on the control of the compressor frequency control unit 42. If it raises to this target frequency, the control part 41 will drive the compressor 7 for predetermined time (for example, 30 seconds) with a target frequency (step S10). This predetermined time is set as a time during which the oil accumulated in the evaporator can be sufficiently returned to the compressor, and can be appropriately changed according to the arrangement relationship between the evaporator and the compressor, the pipe length, and the like. It is.

By operating the compressor 7 at the target frequency, all of the refrigerant discharged from the compressor 7 passes through the gas cooler 9 and flows into the first evaporator 19 of the first cooling greenhouse 2 set to be heated. Therefore, the oil accumulated in the first evaporator 19 is circulated through the refrigeration cycle 5 together with the refrigerant and returned to the compressor 7 while being dissolved in the refrigerant flowing into the first evaporator 19. As a result, even when there is a product storage chamber set to be heated, the oil accumulated in the evaporator disposed in this chamber can be periodically returned to the compressor 7, and oil shortage in the compressor 7 can be reduced. Can be prevented.
Further, while the refrigerant is flowing into the first evaporator 19, the control unit 41 is in a state in which the first evaporator blower fan 28 is stopped, and thus the evaporation of the refrigerant in the first evaporator 19 is suppressed. The temperature in the first cooling greenhouse 2 set for heating is prevented from dropping more than necessary.
In this control, oil return is performed by operating the compressor 7 at a predetermined target frequency. This target frequency is the same frequency as the target frequency after starting the compressor 7 during normal cooling operation. It is preferable to do. In this configuration, it is not necessary to set a dedicated target frequency for oil return control, and the compressor 7 may be normally started, so that the control configuration can be simplified. Further, in the present embodiment, the compressor 7 uses an inverter type variable frequency compressor, but a constant speed type compressor may of course be used.

Subsequently, the control unit 41 opens the second electromagnetic valve 14 of the second cooling greenhouse 3 and closes the first electromagnetic valve 13 of the first cooling greenhouse 2 and the third electromagnetic valve 15 of the cooling chamber 4. The compressor 7 is further operated for a predetermined time (for example, 30 seconds) (step S11). According to this, the refrigerant discharged from the compressor 7 then flows into the second evaporator 20 of the second cooling greenhouse 3 after passing through the gas cooler 9. Therefore, the oil accumulated in the second evaporator 20 is circulated through the refrigeration cycle 5 together with the refrigerant and returned to the compressor 7 while being dissolved in the refrigerant flowing into the second evaporator 20. As a result, even when there is a product storage chamber set to be heated, the oil accumulated in the evaporator disposed in this chamber can be periodically returned to the compressor 7, and oil shortage in the compressor 7 can be reduced. Can be prevented.
Since the second evaporator blower fan 29 is also stopped while the refrigerant is flowing into the second evaporator 20, the second evaporator 20 is set to be heated by suppressing the evaporation of the refrigerant in the second evaporator 20. The temperature in the cooling chamber 3 is not lowered more than necessary.
In this configuration, when there are two product storage chambers that are heated, the oil return is performed one by one in order to prevent the amount of refrigerant flowing through one evaporator from being reduced. It is possible to suppress oil remaining in the water.

Then, the control part 41 will complete | finish oil return control, if predetermined time (30 second) passes after opening the 2nd electromagnetic valve 14 of the 2nd cooling greenhouse 3 (step S12). In this case, the control unit 41 shifts to normal operation control without stopping the operation of the compressor 7.
Specifically, the third electromagnetic valve 15 in the cooling only chamber 4 is opened, the third evaporator blower fan 30 is operated, and the cooling operation of the cooling only chamber 4 is started. Further, the first electromagnetic valve 13 of the first cooling greenhouse 2 and the second electromagnetic valve 14 of the second cooling greenhouse 3 are closed, respectively, and energization of the first electric heater 34 and the second electric heater 35 is started. And the 1st evaporator ventilation fan 28 and the 2nd evaporator ventilation fan 29 are drive | operated, and the heating operation of the 1st cooling greenhouse 2 and the 2nd cooling greenhouse 3 is started.
In this configuration, following the oil return control, the operation of the compressor 7 is stopped without stopping the operation, so that the normal cooling and heating control operation is performed. The cooling and heating control operation can be started, and the temperature fluctuation of the product can be minimized.

On the other hand, in the determination of step 8, when there are not two product storage chambers that are heated, that is, when there is one (step S8; No), the control unit 41 determines the corresponding product storage chamber (for example, the first cooling chamber). The first solenoid valve 13 of the heating chamber 2) is opened, the second solenoid valve 14 of the remaining second cooling chamber 3 and the third solenoid valve 15 of the cooling chamber 4 are closed, and the operation of the compressor 7 is started. (Step S13).
Then, after starting the compressor 7 at a predetermined starting frequency, the control unit 41 gradually increases the operating frequency to the target frequency, and operates the compressor 7 at the target frequency for a predetermined time (for example, 30 seconds) (step) S14). Thereby, all the refrigerant | coolants discharged from the compressor 7 pass the gas cooler 9, and flow in into the 1st evaporator 19 of the 1st cooling greenhouse 2 set by heating. For this reason, the oil accumulated in the first evaporator 19 is dissolved in the refrigerant flowing into the first evaporator 19, circulated through the refrigeration cycle 5 together with the refrigerant, and returned to the compressor 7. The oil shortage inside can be prevented.
While the refrigerant is flowing into the first evaporator 19, the control unit 41 is in a state in which the first evaporator blower fan 28 is stopped, and therefore, the evaporation of the refrigerant in the first evaporator 19 is suppressed. The temperature in the 1st cooling greenhouse 2 set by heating does not fall more than necessary.
Thereafter, the process proceeds to step S12 described above, and the process ends.

  As described above, according to the present embodiment, the first cooling greenhouse 2 and the second cooling greenhouse 3 that store products by switching to cooling or heating, and the cooling exclusive chamber 4 that stores cooled products. The first to third evaporators 19, 20, and 21 of the refrigeration cycle 5 are arranged in the first cooling greenhouse 2, the second cooling greenhouse 3, and the cooling exclusive chamber 4, respectively, and the first cooling In the vending machine 100 in which the first to second electric heaters 34 and 35 are arranged in the heating chamber 2 and the second cooling heating chamber 3, the heating setting is performed when the first cooling heating chamber 2 is set to be heated. In addition, since the first evaporator 19 of the first cooling greenhouse 2 is provided with the control unit 41 that periodically circulates the refrigerant and returns the oil accumulated in the first evaporator 19 to the compressor 7, the heating is set. In addition, a large amount of oil is accumulated in the first evaporator 19 of the first cooling chamber 2. It can be eliminated the situation can be prevented oil shortage in the compressor 7.

  Further, according to the present embodiment, the control unit 41 is arranged close to the first evaporator 19 while the refrigerant is circulated through the first evaporator 19 of the first cooling greenhouse 2. Since the operation of the blower fan 28 is stopped, evaporation of the refrigerant in the first evaporator 19 can be suppressed, and the temperature in the first cooling greenhouse 2 set for heating can be prevented from being lowered more than necessary.

  Moreover, according to this embodiment, the control part 41 distribute | circulates a refrigerant | coolant to the 1st evaporator 19 of the 1st cooling greenhouse 2 on the condition that the defrost of the 3rd evaporator 21 of the cooling exclusive room 4 was complete | finished. Therefore, the control for returning the oil accumulated in the first evaporator 19 to the compressor 7 can be performed at midnight when there is little merchandise sales, and the first cooling greenhouse 2 and the second cooling of the vending machine 100 can be performed. It is possible to suppress temperature fluctuations of the products stored in the heating chamber 3 and the cooling room 4 as much as possible. Furthermore, the oil that has flowed back to the first evaporator 19 from the compressor 7 stopped due to defrosting can also be returned to the compressor 7 together.

  In addition, according to the present embodiment, when there are a plurality of the first cooling greenhouse 2 and the second cooling greenhouse 3 that are set to be heated, the control unit 41 controls the first cooling greenhouse 2 and the second cooling greenhouse 3. Since the refrigerant is circulated sequentially through the first evaporator 19 and the second evaporator 20, the amount of refrigerant flowing through each of the first evaporator 19 and the second evaporator 20 is prevented from being reduced. The remaining oil in the second evaporator 20 can be suppressed.

  In addition, according to the present embodiment, after a predetermined time has elapsed from the start of the refrigerant flow to the second evaporator 20 of the second cooling greenhouse 3, the operation of the compressor 7 is continued while the operation of the compressor 7 is continued. The flow of the refrigerant to the first evaporator 19 and the second evaporator 20 of the second cooling greenhouse 3 is interrupted, energization to the first electric heater 34 and the second electric heater 35 is started, and the cooling exclusive chamber 4, the normal cooling and heating control operation can be started earlier by the restart prohibition time due to the stop of the compressor 7, and the temperature fluctuation of the product can be reduced. Can be minimized.

Although this embodiment demonstrated the structure provided with an electric heater as a heating part which heats a cooling warming room, it is not restricted to this, The heat exchanger which heats using the waste heat which arises by cooling ( It is good also as a structure which provided the heating part.
FIG. 4 is a refrigerant circuit diagram of a vending machine 200 according to another embodiment. In FIG. 4, the same components as those of the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.
The difference from the above-described embodiment will be described. The refrigerant discharge pipe 24 of the compressor 7 is provided with a three-way valve 50, and the three-way valve 50 has an interior disposed in the first cooling greenhouse 2. A refrigerant inlet side pipe 52 of the gas cooler 51 is connected, and a refrigerant outlet side pipe 53 of the internal gas cooler 51 is connected to the refrigerant discharge pipe 24 between the three-way valve 50 and the gas cooler 9.
The internal gas cooler 51 is formed as an integrated heat exchanger that shares the fins with the first evaporator 19.
The high-temperature and high-pressure refrigerant discharged from the compressor 7 flows into the internal gas cooler 51, whereby the inside of the first cooling greenhouse 2 can be heated, and the internal gas cooler 51 serves as a heating unit. Function.

Further, the gas cooler 9 is provided with an outside-compartment evaporator 58 that shares the fins with the gas cooler 9, and a refrigerant outlet side pipe 54 of the outside-compartment evaporator 58 is connected to the refrigerant suction pipe 23 of the compressor 7. Yes. The refrigerant inlet side pipe 55 of the outside evaporator 58 has an outside capillary tube 56 and an outside solenoid valve 57 and is connected to the outlet side pipe 26 of the gas cooler 9.
The outside evaporator 58 is an evaporator for achieving a heat balance when the refrigerant is circulated through the inside gas cooler 51 in order to heat the first cooling greenhouse 2. The refrigerant is circulated to the outside evaporator 58 after being opened.

Thus, as the heating unit for heating the first cooling greenhouse 2, not only the first electric heater 34 but also the internal gas cooler 51 for heating using waste heat generated by cooling in the refrigeration cycle is provided. It can also be configured.
Even in this configuration, since oil is accumulated in the evaporator set to be heated, the oil can be returned to the compressor 7 by periodically circulating the refrigerant through the evaporator.

Moreover, although the above-mentioned embodiment demonstrated the structure which used the carbon dioxide refrigerant as a refrigerant | coolant, if a refrigerant | coolant is an existing refrigerant | coolant containing a HFC refrigerant | coolant, it will not be limited.
Further, in the above-described embodiment, the oil return control is performed on the condition that the defrosting of the evaporator of the commodity storage room that is set to be cooled is completed, but other conditions may be used as a starting point.
In the above-described embodiment, the electromagnetic valve as the opening / closing means and the capillary tube as the pressure reducing means are provided. However, an electric expansion valve whose opening degree can be freely changed is provided, and the electric expansion valve is connected to the opening / closing means. It is good also as a structure which has a function with a pressure reduction means together.

2 First cooling chamber (hot / cold switching product storage room)
3 Second cooling greenhouse (hot / cold switching product storage room)
4 Cooling room (cold product storage room)
DESCRIPTION OF SYMBOLS 5 Refrigerating cycle 7 Compressor 9 Gas cooler 13 1st solenoid valve 14 2nd solenoid valve 15 3rd solenoid valve 19 1st evaporator 20 2nd evaporator 21 3rd evaporator 28 1st evaporator ventilation fan (blowing fan)
29 Second evaporator blower fan (fan)
30 Third evaporator blower fan (fan)
34 First electric heater (heating unit)
35 Second electric heater (heating unit)
40 controller 41 control unit (oil return control unit)
42 Compressor frequency controller 51 Internal gas cooler (heating unit)
100, 200 vending machines

Claims (5)

Equipped with a hot / cold switching product storage room and a cold dedicated product storage room, each of these product storage rooms is provided with a refrigeration cycle evaporator, and the hot / cold switching product storage room is heated. In a vending machine with a heating unit that
When the hot / cold switching product storage chamber is set to warm, the refrigerant accumulated in the evaporator is compressed by circulating refrigerant periodically or irregularly in the evaporator of the hot / cold switching product storage chamber. An automatic vending machine comprising an oil return control unit for returning to the machine.   The oil return control unit stops the operation of a blower fan disposed close to the evaporator while the refrigerant is circulated through the evaporator of the hot / cold switching product storage chamber. The vending machine according to 1.   2. The oil return control unit circulates a refrigerant through the evaporator of the hot / cold switching product storage chamber on condition that the defrosting of the evaporator of the cold dedicated product storage chamber is completed. Or vending machine according to 2.   4. When there are a plurality of hot / cold switching product storage chambers, the oil return control unit causes the refrigerant to flow through each of the evaporators in the hot / cold switching product storage chambers. The vending machine described in Crab.   After a predetermined time has elapsed from the start of the flow of the refrigerant to the evaporator of the hot / cold switching product storage chamber, the refrigerant flows to the evaporator of the hot / cold switching product storage chamber while continuing to operate the compressor. 5. The vending machine according to claim 1, wherein the vending machine shifts to a normal operation in which the heating unit is shut off to operate the heating unit and the refrigerant is circulated through the evaporator of the cold-dedicated product storage chamber. .

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