Automatic selling machine

Abstract

To provide an automatic selling machine which can inhibit excessive temperature rise in a storage where products are stored during defrosting of evaporators.SOLUTION: An automatic selling machine 100 includes: a storage 5 in which products 105 are stored; a compressor 21 which compresses a refrigerant; a condenser 22 which condenses the refrigerant discharged from the compressor 21; expansion valves 24a to 24c which expand the refrigerant condensed by the condenser 22; evaporators 27a to 27c which evaporate the refrigerant expanded by the expansion valves 24a to 24c; and a control unit 8 which performs defrosting control of the evaporators 27a to 27c by causing the refrigerant expanded by the expansion valves 24a to 24c to flow into the evaporators 27a to 27c and adjusting opening degrees of the expansion valves 24a to 24c so that temperatures of the refrigerant flowing into the evaporators 27a to 27c become a refrigerant temperature during defrosting, which is higher than a temperature in the storage 5 during cooling, when the evaporators 27a to 27c are defrosted.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to vending machines. [Background technology]

[0002] BACKGROUND ART Conventionally, vending machines have been known (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses a vending machine equipped with a refrigerator, a cooler (evaporator), and a defrost control device including a thermistor for detecting the temperature of the cooler. The cooler cools the refrigerator by being supplied with refrigerant. The defrost control device performs defrosting to remove frost that has adhered to the cooler by stopping the supply of refrigerant to the cooler. If the temperature of the cooler detected by the thermistor after a predetermined time has elapsed since the start of defrosting is equal to or lower than a set temperature, defrosting continues, and if the temperature of the cooler detected by the thermistor exceeds the set temperature, defrosting is stopped and refrigerant is supplied to the cooler. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 5-87436 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the vending machine described in Patent Document 1, the cooler is defrosted by stopping the supply of refrigerant to the cooler until at least a predetermined time has passed. Therefore, when the cooler (evaporator) is defrosted, there is a possibility that the temperature inside the cooling chamber (storage chamber) where the products are stored may rise excessively. Therefore, it is desirable to prevent the temperature inside the storage chamber where the products are stored from rising excessively when the evaporator is defrosted.

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a vending machine that can prevent the temperature inside the storage compartment in which products are stored from rising excessively when the evaporator is defrosted. [Means for solving the problem]

[0007] In order to achieve the above object, a vending machine according to one aspect of the present invention comprises a storage compartment in which products are stored, a compressor that compresses a refrigerant, a condenser that condenses the refrigerant discharged from the compressor, an expansion valve that expands the refrigerant condensed by the condenser, an evaporator that evaporates the refrigerant expanded by the expansion valve, and a control unit that, when defrosting the evaporator, causes the refrigerant expanded by the expansion valve to flow into the evaporator and adjusts the opening of the expansion valve so that the temperature of the refrigerant flowing into the evaporator becomes a defrosting refrigerant temperature that is higher than the temperature during cooling in the storage compartment, thereby performing defrosting control of the evaporator.

[0008] In a vending machine according to one aspect of the present invention, as described above, the control unit controls defrosting of the evaporator by causing refrigerant expanded by the expansion valve to flow into the evaporator and adjusting the opening of the expansion valve so that the temperature of the refrigerant flowing into the evaporator is a defrosting refrigerant temperature that is higher than the cooling temperature of the storage compartment. This allows refrigerant with a defrosting refrigerant temperature higher than the cooling temperature of the storage compartment to flow into the evaporator, thereby defrosting the evaporator and cooling the air in the storage compartment through evaporation of the refrigerant in the evaporator without stopping the refrigerant supply. Therefore, an excessive rise in the temperature inside the storage compartment where products are stored can be prevented when defrosting the evaporator.

[0009] In the vending machine according to the above aspect, the defrosting refrigerant temperature is preferably higher than the cooling temperature in the storage compartment and lower than the target temperature in the storage compartment, and the control unit is configured to control the defrosting of the evaporator by adjusting the opening of the expansion valve so that the temperature of the refrigerant flowing into the evaporator is the defrosting refrigerant temperature. With this configuration, while the evaporator is defrosted, refrigerant with a defrosting refrigerant temperature higher than the cooling temperature in the storage compartment and lower than the target temperature in the storage compartment is evaporated in the evaporator to cool the air in the storage compartment, thereby appropriately preventing the temperature in the storage compartment from rising above the target temperature. Therefore, an excessive rise in the temperature in the storage compartment in which the products are stored can be effectively prevented during defrosting of the evaporator.

[0010] In this case, preferably, the defrosting refrigerant temperature is higher than 0°C and lower than the target temperature in the storage compartment, and the control unit is configured to control defrosting of the evaporator by adjusting the opening of the expansion valve so that the temperature of the refrigerant flowing into the evaporator is the defrosting refrigerant temperature. With this configuration, refrigerant with a defrosting refrigerant temperature higher than 0°C and lower than the target temperature in the storage compartment flows into the evaporator, thereby effectively defrosting the evaporator while appropriately preventing the temperature in the storage compartment from rising above the target temperature by cooling the air in the storage compartment through evaporation of the refrigerant in the evaporator. Therefore, during defrosting of the evaporator, it is possible to effectively defrost the evaporator while appropriately preventing the temperature in the storage compartment where the products are stored from rising excessively.

[0011] The vending machine according to the above aspect preferably further includes a blower that sends air to the evaporator and sends the air cooled in the evaporator into the storage compartment, and the control unit is configured to, when defrosting the evaporator, adjust the opening of the expansion valve so that the temperature of the refrigerant flowing into the evaporator is equal to the defrosting refrigerant temperature, and to perform defrost control of the evaporator while blowing air to the evaporator with the blower to melt frost that has adhered to the evaporator. With this configuration, the evaporator can be efficiently defrosted by blowing air to the evaporator with the blower to melt frost that has adhered to the evaporator. Therefore, when defrosting the evaporator, efficient defrosting of the evaporator with the blower can shorten the time required for defrost control of the evaporator, thereby further preventing the temperature in the storage compartment where the products are stored from rising excessively.

[0012] The vending machine according to the above aspect preferably further includes an internal storage compartment temperature detection unit that detects the temperature inside the storage compartment, and the control unit is configured to terminate defrost control of the evaporator when the temperature detected by the internal storage compartment temperature detection unit reaches a predetermined first defrost stop temperature that is higher than the target temperature inside the storage compartment during defrosting of the evaporator, and adjust the aperture of the expansion valve so that the temperature detected by the internal storage compartment temperature detection unit reaches the target temperature inside the storage compartment. With this configuration, the time until the temperature detected by the internal storage compartment temperature detection unit reaches the first defrost stop temperature can be secured as the time for defrosting, and by terminating defrost control of the evaporator when the temperature reaches the first defrost stop temperature, it is possible to further prevent the temperature inside the storage compartment in which the products are stored from rising excessively.

[0013] The vending machine according to the above aspect preferably further includes a first temperature detection unit that detects the temperature of the refrigerant inlet of the evaporator and an internal storage temperature detection unit that detects the temperature inside the storage compartment. The control unit is configured to terminate the defrost control of the evaporator and adjust the opening of the expansion valve so that the temperature detected by the internal storage temperature detection unit becomes the target temperature inside the storage compartment when the temperature detected by the first temperature detection unit is equal to or higher than a predetermined second defrost stop temperature higher than 0°C and the temperature detected by the internal storage temperature detection unit is constant or decreasing during defrosting of the evaporator. Here, clogging due to the accumulation of frost (ice) between the fins of the evaporator reduces the cooling capacity of the evaporator. In this case, if the defrost control of the evaporator is terminated without clearing the clogging of the evaporator by defrosting the evaporator, the temperature inside the storage compartment may increase rather than decrease during cooling after the defrost control of the evaporator is terminated. Therefore, if the defrost control of the evaporator is configured to be terminated when the temperature detected by the first temperature detection unit is equal to or higher than the second defrost stop temperature and the temperature detected by the storage compartment temperature detection unit is constant or decreasing, it can be assumed that the evaporator has been unclogged because the temperature detected by the first temperature detection unit is equal to or higher than the second defrost stop temperature and the temperature detected by the storage compartment temperature detection unit is constant or decreasing. In other words, it can be assumed that defrosting of the evaporator has been completed because the temperature detected by the storage compartment temperature detection unit is constant or decreasing. Therefore, it is possible to terminate the defrost control of the evaporator at an appropriate timing.

[0014] The vending machine according to the above aspect preferably further includes a first temperature detection unit that detects the temperature of a refrigerant inlet of the evaporator, a second temperature detection unit that detects the temperature of a refrigerant outlet of the evaporator, and an internal storage temperature detection unit that detects the temperature inside the storage compartment, and the control unit is configured to terminate defrost control of the evaporator when a difference between the temperature detected by the first temperature detection unit and the temperature detected by the second temperature detection unit is equal to or greater than a predetermined temperature during defrosting of the evaporator, and adjust the aperture of the expansion valve so that the temperature detected by the internal storage temperature detection unit becomes a target temperature inside the storage compartment. Here, the difference between the refrigerant inlet temperature detected by the first temperature detection unit and the refrigerant outlet temperature detected by the second temperature detection unit means that the refrigerant temperature of the refrigerant flowing into the evaporator has risen above the saturation temperature (superheated), and it can be said that heat exchange via the refrigerant in the evaporator is sufficient. Therefore, if the defrost control of the evaporator is configured to end when the difference between the temperature detected by the first temperature detection unit and the temperature detected by the second temperature detection unit is equal to or greater than a predetermined temperature during defrosting of the evaporator, it can be estimated that the frost (ice) adhering to the evaporator has melted due to the presence of a degree of superheat, and defrosting has been completed. Therefore, it is possible to accurately determine the completion of defrosting due to the melting of the frost (ice) adhering to the evaporator, and therefore it is possible to end the defrost control of the evaporator at an appropriate timing.

[0015] The vending machine according to the above aspect preferably further includes a first temperature detection unit that detects the temperature of a refrigerant inlet to the evaporator, and the control unit is configured to perform cooling-stop defrosting, which is different from defrosting by defrost control, by stopping operation of the compressor when defrosting of the evaporator starts, and after cooling-stop defrosting starts, start operation of the compressor based on the temperature detected by the first temperature detection unit or the passage of a predetermined time, and after starting operation of the compressor after cooling-stop defrosting starts, perform cooling-continuation defrosting as defrosting by defrost control by adjusting the pressure of the refrigerant flowing out of the expansion valve so that the temperature of the refrigerant flowing into the evaporator becomes the defrost-time refrigerant temperature. With this configuration, by performing cooling-stop defrosting when defrosting of the evaporator starts, frost adhering to the evaporator is melted by the heat of the refrigerant with an increased temperature, and by switching from cooling-stop defrosting to cooling-continuation defrosting based on the temperature detected by the first temperature detection unit or the passage of a predetermined time, refrigerant at the defrost-time refrigerant temperature can be flowed into the evaporator to defrost the evaporator while cooling the storage compartment. Therefore, the defrosting time of the evaporator can be shortened compared to when cooling stop defrosting is not performed at the start of defrosting of the evaporator.

[0016] In this case, the control unit is preferably configured to start operation of the compressor when, after the start of cooling-stop defrosting, the temperature detected by the first temperature detection unit becomes equal to or higher than a preset third defrost-stop temperature that is higher than the target temperature inside the storage compartment, or when a predetermined time has elapsed.With this configuration, when the temperature detected by the first temperature detection unit becomes equal to or higher than the third defrost-stop temperature, the control unit switches from cooling-stop defrosting to cooling-continue defrosting, thereby making it possible to further prevent the temperature inside the storage compartment where the products are stored from rising excessively when defrosting the evaporator. [Effects of the Invention]

[0017] According to the present invention, as described above, it is possible to provide a vending machine that can prevent the temperature inside the storage compartment in which products are stored from rising excessively. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a perspective view of a vending machine according to a first embodiment. FIG. [Figure 2] 1 is a cross-sectional view of a vending machine according to a first embodiment. [Figure 3] 1 is a refrigerant circuit diagram showing a schematic configuration of a vending machine according to a first embodiment. [Figure 4] FIG. 4 is a refrigerant circuit diagram showing the flow of refrigerant when CCC operation is performed in the refrigerant circuit diagram shown in FIG. 3. [Figure 5] FIG. 4 is a refrigerant circuit diagram showing the flow of refrigerant when HCC operation is performed in the refrigerant circuit diagram shown in FIG. 3. [Figure 6] 4 is a time chart for explaining defrosting control by a control unit in the first embodiment. [Figure 7] 6 is a time chart for explaining defrosting control in a comparative example. [Figure 8] 10 is a time chart for explaining defrosting control by a control unit in a second embodiment. [Figure 9] FIG. 10 is a refrigerant circuit diagram showing a schematic configuration of a vending machine according to a third embodiment. [Figure 10] 10 is a time chart for explaining a first example of defrosting control by a control unit in the fourth embodiment. [Figure 11] 10 is a time chart for explaining a second example of defrosting control by the control unit in the fourth embodiment. [Figure 12] 10 is a time chart for explaining a third example of defrosting control by the control unit in the fourth embodiment. [Figure 13] FIG. 10 is a refrigerant circuit diagram showing a schematic configuration of a vending machine according to a first modified example. DETAILED DESCRIPTION OF THE INVENTION

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

[0020] [First embodiment] (Overall configuration of the vending machine) The configuration of a vending machine 100 according to a first embodiment of the present invention will be described with reference to FIGS.

[0021] The vending machine 100 according to this embodiment is a machine that cools or heats (warms) products 105, such as canned drinks or PET bottled drinks, before selling them. The vending machine 100 also includes a refrigerant circuit device 6 (see FIG. 3) with a heat pump function, and uses a heat utilization system in which heat obtained when cooling the products 105 in the cooling compartment using the refrigerant circuit device 6 is transferred to the heating compartment to heat the products 105 in the heating compartment.

[0022] 1 and 2, the vending machine 100 includes a main body cabinet 1, an outer door 2, an inner door 3, a partition member 4, a storage compartment 5, a refrigerant circuit device 6, a machine room 7, and a control unit 8 (see FIG. 3). As shown in FIG. 1, the storage compartment 5 is made up of a right compartment 5a, a middle compartment 5b, and a left compartment 5c that are independent of each other, and each compartment is configured to store a product 105.

[0023] The right compartment 5a is located on the right side (X1 side), the middle compartment 5b is located in the center, and the left compartment 5c is located on the left side (X2 side). The right compartment 5a has two rows, the middle compartment 5b has one row, and the left compartment 5c has three rows. In the vending machine 100, the right compartment 5a and the middle compartment 5b are dedicated to cooling, and the left compartment 5c is a dual-purpose cooling / heating compartment. In this specification, the right and left sides refer to the right (X1 side) and left (X2 side), respectively, when viewing the vending machine 100 from the front (the side facing the outer door 2).

[0024] The right compartment 5a, the middle compartment 5b, and the left compartment 5c are separated from one another by a heat-insulating partition member 5d. The refrigerant circuit device 6 is configured to individually heat or cool the right compartment 5a, the middle compartment 5b, and the left compartment 5c under the control of the control unit 8.

[0025] The interior of the main body cabinet 1 is divided into upper and lower compartments by a partition member 4, and is therefore divided into a storage compartment 5 arranged on the upper side and a machine room 7 arranged on the lower side.

[0026] As shown in Figure 2, a vertically long product storage rack 5e is provided in the storage cabinet 5 (right storage cabinet 5a). Note that Figure 2 shows the internal structure (cross-sectional view) of the storage cabinet 5 in the right storage cabinet 5a section, but the internal structure of the middle storage cabinet 5b is also substantially similar to that of the right storage cabinet 5a. The internal structure of the left storage cabinet 5c is also substantially similar to that of the right storage cabinet 5a, except that an auxiliary heater is provided. Furthermore, a heat insulating material 9 is provided on the inner surface of the main cabinet 1 so as to surround the product storage rack 5e.

[0027] A discharge chute 10 is disposed at the bottom of the storage cabinet 5 to guide the products 105 to the product outlet 2a. This allows the vending machine 100 to discharge the products 105 from the bottom side of the product storage rack 5e to the outside of the storage cabinet (product outlet 2a) via the discharge chute 10. The discharge chute 10 also has multiple through-holes (not shown) that allow the air inside the storage cabinet to circulate.

[0028] The storage compartment 5 is provided with rear ducts 70a to 70c that extend vertically along the rear surfaces of the right compartment 5a, middle compartment 5b, and left compartment 5c, respectively, and that guide the internal air that has cooled the interior of the compartment to internal heat exchangers 27a to 27c, which will be described later. The internal heat exchanger 27a of the right compartment 5a, the internal heat exchanger 27b of the middle compartment 5b, and the internal heat exchanger 27c of the left compartment 5c are examples of "evaporators" in the claims.

[0029] As shown in FIG. 3, the right compartment 5a is provided with an internal storage temperature detector 80a. The internal storage temperature detector 80a is configured to detect the temperature inside the right compartment 5a. The middle compartment 5b is provided with an internal storage temperature detector 80b. The internal storage temperature detector 80b is configured to detect the temperature inside the middle compartment 5b. The left compartment 5c is provided with an internal storage temperature detector 80c. The internal storage temperature detector 80c is configured to detect the temperature inside the left compartment 5c.

[0030] The refrigerant circuit device 6 has the function of cooling or heating (warming) the products 105 stored in the storage compartment 5. The refrigerant circuit device 6 includes a refrigerant circuit 60 made up of a main circuit 20, a high-pressure refrigerant introduction circuit 30, and a heat dissipation circuit 40. A predetermined amount of refrigerant is sealed in the refrigerant circuit 60. One example of the refrigerant is R1234yf. However, the refrigerant in the refrigerant circuit 60 is not limited to R1234yf, and various other refrigerants can be used.

[0031] The main circuit 20 is made up of a compressor 21, a flow path switching valve 61, an external heat exchanger 22, a dryer 23, electronic expansion valves 24a to 24c, a check valve 25, capillaries 26a to 26c, internal heat exchangers 27a to 27c, and refrigerant piping 28 that sequentially connects these components. Note that the external heat exchanger 22 is an example of a "condenser" in the claims, and the electronic expansion valve 24a upstream of the internal heat exchanger 27a, the electronic expansion valve 24b upstream of the internal heat exchanger 27b, and the electronic expansion valve 24c upstream of the internal heat exchanger 27c are examples of "expansion valves" in the claims.

[0032] As shown in Fig. 2, compressor 21 and external heat exchanger 22 are disposed in machine room 7 outside (outside) storage compartment 5. In addition, internal heat exchangers 27a, 27b, and 27c (see Fig. 3) are disposed in the inner bottom regions and on the far side (Y2 side) of right compartment 5a, middle compartment 5b, and left compartment 5c, respectively.

[0033] The refrigerant circuit device 6 further includes an external fan 71 and internal fans 72a to 72c. The internal fan 72a provided to correspond to the internal heat exchanger 27a, the internal fan 72b provided to correspond to the internal heat exchanger 27b, and the internal fan 72c provided to correspond to the internal heat exchanger 27c are examples of "blowers" in the claims.

[0034] The external fan 71 is disposed between the compressor 21 and the external heat exchanger 22 in the front-to-rear direction (Y direction) inside the machine room 7. The external fan 71 is configured to draw air from the front side (Y1 direction side) of the machine room 7, absorb condensation heat in the external heat exchanger 22 with the drawn-in air, and also absorb exhaust heat from the compressor 21 and exhaust the air to the rear side (Y2 direction side) of the machine room 7.

[0035] The internal fan 72a is disposed in front of (on the Y1 side of) the internal heat exchanger 27a. The air cooled by the internal heat exchanger 27a is sent to the right compartment 5a by the internal fan 72a, recovered (sucked) into the rear duct 70a, and sent towards the internal heat exchanger 27a by the internal fan 72a. The internal fan 72b is disposed in front of the internal heat exchanger 27b. The air cooled by the internal heat exchanger 27b is sent to the middle compartment 5b by the internal fan 72b, recovered (sucked) into the rear duct 70b, and sent towards the internal heat exchanger 27b by the internal fan 72b.

[0036] The internal fan 72c is disposed in front of the internal heat exchanger 27c. The air cooled by the internal heat exchanger 27c is sent to the left compartment 5c by the internal fan 72c, collected (sucked) into the rear duct 70c, and sent toward the internal heat exchanger 27c by the internal fan 72c. An auxiliary heater 73c (see FIG. 3) is provided in front of (on the Y1 side of) the internal heat exchanger 27c. The auxiliary heater 73c is used to provide auxiliary heating inside the left compartment 5c, and is not used to defrost the internal heat exchanger 27c, which will be described later.

[0037] 3 is configured to compress refrigerant drawn in through a suction port, convert it into a high-temperature, high-pressure refrigerant, and discharge it. The compressor 21 is an inverter-controlled compressor that can control the amount of refrigerant discharged based on rotational speed control.

[0038] The external heat exchanger 22 is configured to condense (liquefy) the refrigerant by heat exchange between the refrigerant and outside air blown by the external fan 71. In other words, the external heat exchanger 22 functions as a condenser that condenses the refrigerant and thereby releases heat to the outside of the cabinet.

[0039] The electronic expansion valves 24a-24c and the capillaries 26a-26c are provided in the paths of the internal heat exchangers 27a-27c, respectively, and have the functions of controlling the flow rate of the refrigerant by adjusting the aperture of the electronic expansion valves 24a-24c, respectively, and depressurizing the refrigerant condensed in the external heat exchanger 22 to adiabatically expand it. The electronic expansion valves 24a-24c are configured to depressurize the refrigerant flowing into the internal heat exchangers 27a-27c, respectively, and to adjust the temperature of the refrigerant. That is, increasing (opening) the aperture of the electronic expansion valves 24a-24c increases the refrigerant temperature (inlet temperatures of the internal heat exchangers 27a-27c increase), and decreasing (throttling) the aperture of the electronic expansion valves 24a-24c decreases the refrigerant temperature (inlet temperatures of the internal heat exchangers 27a-27c decrease). A check valve 25 is connected between the electronic expansion valve 24c and the capillary 26c.

[0040] The internal heat exchangers 27a and 27b function as evaporators that absorb heat from the right compartment 5a and the middle compartment 5b, respectively, by evaporating the two-phase gas-liquid refrigerant that flows in. The internal heat exchanger 27c evaporates the two-phase gas-liquid refrigerant that flows in when refrigerant expanded by the electronic expansion valve 24c and the capillary 26c passes through it (during CCC operation). That is, the internal heat exchanger 27c functions as an evaporator that absorbs heat from the left compartment by evaporating the refrigerant during cooling operation. Furthermore, the internal heat exchanger 27c condenses (liquefies) the refrigerant that flows in when refrigerant compressed by the compressor 21 passes through it (during HCC operation). That is, the internal heat exchanger 27c functions as a condenser that releases heat into the left compartment 5c (heats the left compartment 5c) during heating operation. In this specification, CCC operation refers to an operation in which the air inside all of the right compartment 5a, middle compartment 5b, and left compartment 5c is cooled. Also, in this specification, HCC operation refers to an operation in which the air inside the left compartment 5c is heated and the air inside the right compartment 5a and middle compartment 5b is cooled.

[0041] The internal heat exchanger 27a is provided with a first temperature detection unit 81a. The first temperature detection unit 81a is provided on the refrigerant pipe 28 near the refrigerant inlet of the internal heat exchanger 27a. The first temperature detection unit 81a is configured to detect the temperature near the refrigerant inlet of the internal heat exchanger 27a. The internal heat exchanger 27b is provided with a first temperature detection unit 81b. The first temperature detection unit 81b is provided on the refrigerant pipe 28 near the refrigerant inlet of the internal heat exchanger 27b. The first temperature detection unit 81b is configured to detect the temperature near the refrigerant inlet of the internal heat exchanger 27b. The internal heat exchanger 27c is provided with a first temperature detection unit 81c. The first temperature detection unit 81c is provided on the refrigerant pipe 28 near the refrigerant inlet of the internal heat exchanger 27c. The first temperature detection unit 81c is configured to detect the temperature near the refrigerant inlet of the internal heat exchanger 27c.

[0042] An electromagnetic valve 62 is provided on the outlet side of the internal heat exchanger 27c. The electromagnetic valve 62 is an openable and closable valve element, and is opened and closed under the control of the control unit 8.

[0043] The high-pressure refrigerant introduction circuit 30 is a path that directly connects the discharge side of the compressor 21 and the inlet side of the internal heat exchanger 27c. Specifically, the high-pressure refrigerant introduction circuit 30 includes a flow path switching valve 61, which is a three-way valve, and a high-pressure refrigerant introduction pipe 31. The high-pressure refrigerant introduction circuit 30 is used to heat (warm) the air inside the left compartment 5c by introducing the refrigerant compressed by the compressor 21 into the internal heat exchanger 27c without passing through the external heat exchanger 22, the electronic expansion valve 24c, or the capillary 26c. The flow path switching valve 61 is a solenoid valve that selectively switches between a first delivery state in which the refrigerant compressed by the compressor 21 is delivered to the external heat exchanger 22 and a second delivery state in which the refrigerant compressed by the compressor 21 is delivered to the high-pressure refrigerant introduction circuit 30.

[0044] The heat dissipation circuit 40 is a path that connects the outlet side of the internal heat exchanger 27c and the inlet side of the external heat exchanger 22 in the main circuit 20. The heat dissipation circuit 40 includes a strainer 41, an electronic expansion valve 42, a capillary 43, and a check valve 44.

[0045] The refrigerant circuit device 6 is configured to cool or heat (warm) the products 105 stored in the storage 5. Specifically, the refrigerant circuit device 6 is configured to be capable of performing CCC operation (cooling only operation) and HCC operation (heat pump operation).

[0046] As shown in Fig. 4, CCC operation is an operation mode in which the right compartment 5a, the middle compartment 5b, and the left compartment 5c are all cooled. In this case, the control unit 8 switches the flow path switching valve 61 to the first delivery state, closes the electronic expansion valve 42, and performs control to open the electronic expansion valves 24a to 24c and the solenoid valve 62. As a result, the refrigerant compressed by the compressor 21 flows sequentially through the flow path switching valve 61, the external heat exchanger 22, the electronic expansion valves 24a to 24c, and the internal heat exchangers 27a to 27c, and is then drawn into the compressor 21. The refrigerant is then compressed by the compressor 21 and repeats the above-described circulation.

[0047] As shown in Figure 5, HCC operation is an operation mode in which the air inside the left compartment 5c, which is the heating target, is heated (warmed), and the right compartment 5a and the middle compartment 5b, which are the cooling targets, are cooled. In this case, the control unit 8 switches the flow path switching valve 61 to the second delivery state, closes the electronic expansion valve 24c and the solenoid valve 62, and opens the electronic expansion valve 42. As a result, the refrigerant compressed by the compressor 21 flows sequentially through the flow path switching valve 61, the high-pressure refrigerant introduction pipe 31, the internal heat exchanger 27c, the external heat exchanger 22, the dryer 23, the electronic expansion valves 24a and 24b, the internal heat exchangers 27a and 27b, and is drawn into the compressor 21. The refrigerant is then compressed by the compressor 21 and repeats the above-described cycle.

[0048] In CCC operation, the left cooling / heating compartment 5c is cooled by evaporating the refrigerant in the internal heat exchanger 27c during cooling operation, and in HCC operation, the left cooling / heating compartment 5c is heated by condensing the refrigerant in the internal heat exchanger 27c during heating operation.

[0049] The control unit 8 is, for example, a CPU (Central Processing Unit). The control unit 8 is configured to perform defrost control of each of the internal heat exchangers 27a to 27c by causing the refrigerant expanded by each of the electronic expansion valves 24a to 24c to flow into each of the internal heat exchangers 27a to 27c during defrosting, and adjusting the opening of each of the electronic expansion valves 24a to 24c so that the temperature of the refrigerant flowing into each of the internal heat exchangers 27a to 27c becomes a refrigerant temperature during defrosting.

[0050] The defrost control of each of the internal heat exchangers 27a to 27c may be configured to be performed simultaneously, or may be configured to be performed alternately and sequentially, or may be configured to be performed independently and individually. Details of the defrost control by the control unit will be described later.

[0051] The defrosting refrigerant temperature is a temperature at which the refrigerant flowing into each of the internal heat exchangers 27a to 27c is higher than the cooling temperatures in the right compartment 5a, the middle compartment 5b, and the left compartment 5c. Specifically, the defrosting refrigerant temperature is a temperature at which the refrigerant flowing into each of the internal heat exchangers 27a to 27c is higher than the cooling temperatures in the right compartment 5a, the middle compartment 5b, and the left compartment 5c, and is lower than the target temperatures in the right compartment 5a, the middle compartment 5b, and the left compartment 5c. More specifically, the defrosting refrigerant temperature is a temperature at which the refrigerant flowing into each of the internal heat exchangers 27a to 27c is higher than 0°C and lower than the target temperatures in the right compartment 5a, the middle compartment 5b, and the left compartment 5c.

[0052] In this embodiment, the temperature of the refrigerant flowing into each of the internal heat exchangers 27a-27c when cooling the right compartment 5a, the middle compartment 5b, and the left compartment 5c is, for example, -10°C to -5°C. Note that the temperature of the refrigerant flowing into each of the internal heat exchangers 27a-27c when cooling the right compartment 5a, the middle compartment 5b, and the left compartment 5c is not limited to -10°C to -5°C. Also, in this embodiment, the target temperature in the right compartment 5a, the middle compartment 5b, and the left compartment 5c is, for example, a temperature below the target product temperature of 5°C. Note that the target product temperature of the products 105 in the right compartment 5a, the middle compartment 5b, and the left compartment 5c is not limited to 5°C. Also, in this embodiment, the refrigerant temperature during defrosting is, for example, 1°C. Note that the refrigerant temperature during defrosting is not limited to 1°C and may be 2°C or 4°C.

[0053] Furthermore, the control unit 8 is configured to perform defrosting control of the internal heat exchangers 27a to 27c while blowing air to the internal heat exchangers 27a to 27c using the internal fans 72a to 72c to melt the frost adhering to the internal heat exchangers 27a to 27c during defrosting of each of the internal heat exchangers 27a to 27c.

[0054] Furthermore, when the temperatures detected by the in-compartment temperature detecting units 80a-80c during defrosting of each of the in-compartment heat exchangers 27a-27c reach a predetermined first defrost stop temperature that is higher than the target temperatures in the right compartment 5a, middle compartment 5b, and left compartment 5c, the control unit 8 is configured to terminate the defrost control of the in-compartment heat exchangers 27a-27c and adjust the apertures of the electronic expansion valves 24a-24c so that the temperatures detected by the in-compartment temperature detecting units 80a-80c reach the target temperatures in the right compartment 5a, middle compartment 5b, and left compartment 5c. In this embodiment, the first defrost stop temperature is, for example, 7°C. However, the first defrost stop temperature is not limited to 7°C.

[0055] (Defrosting control of the internal heat exchanger by the control unit) Defrost control of internal heat exchangers 27a to 27c by control unit 8 will be described with reference to Fig. 6. Defrost control of each of internal heat exchangers 27a to 27c is performed by control unit 8 using similar processing, so for ease of explanation, defrost control of internal heat exchanger 27a in CCC operation by control unit 8 will be described here. Note that in CCC operation, defrost control of internal heat exchangers 27a to 27c is performed by control unit 8, and in HCC operation, defrost control of internal heat exchangers 27a and 27b is performed by control unit 8.

[0056] As shown in FIG. 6, from time t0 to time t1, normal cooling operation is performed to cool the right compartment 5a by circulating the refrigerant in the refrigerant circuit device 6. Specifically, normal cooling control by the control unit 8 switches the flow path switching valve 61 to the first delivery state, closes the electronic expansion valve 42, and opens the electronic expansion valve 24a. As a result, the refrigerant compressed by the compressor 21 flows through the flow path switching valve 61, the external heat exchanger 22, the electronic expansion valve 24a, the capillary 26a, and the internal heat exchanger 27a in this order, and is then drawn into the compressor 21. The refrigerant is then compressed by the compressor 21, and the above-described circulation cycle is repeated. At this time, the control unit 8 adjusts the aperture of the electronic expansion valve 24a so that the temperature of the refrigerant flowing into the internal heat exchanger 27a is between −10°C and −5°C. The control unit 8 also drives the internal fan 72a to send air cooled by the internal heat exchanger 27a to the right compartment 5a.

[0057] Controller 8 starts defrost control (continuous cooling defrosting) when a preset defrost control start time (time t1) arrives. Controller 8 adjusts the aperture of electronic expansion valve 24a at time t1 so that the temperature of the refrigerant flowing into internal heat exchanger 27a becomes the defrosting refrigerant temperature. Specifically, controller 8 increases (opens) the aperture of electronic expansion valve 24a at time t1 to raise the temperature of the refrigerant flowing into internal heat exchanger 27a more than in normal cooling control, and adjusts the aperture of electronic expansion valve 24a so that the temperature of the refrigerant flowing into internal heat exchanger 27a becomes 1°C. Controller 8 also continuously drives internal fan 72a to send air cooled by internal heat exchanger 27a to right compartment 5a, and performs defrost control of internal heat exchanger 27a while melting frost adhering to internal heat exchanger 27a with the air sent to internal heat exchanger 27a.

[0058] When the temperature detected by the storage compartment temperature detection unit 80a reaches the first defrost stop temperature, the control unit 8 stops the defrost control (continuous cooling defrost) and resumes normal cooling control. At time t2, when the temperature detected by the storage compartment temperature detection unit 80a reaches 7°C, the control unit 8 ends the control for adjusting the aperture of the electronic expansion valve 24a so that the temperature of the refrigerant flowing into the storage compartment heat exchanger 27a becomes 1°C, and adjusts the aperture of the electronic expansion valve 24a so that the temperature detected by the storage compartment temperature detection unit 80a becomes the target temperature in the right storage compartment 5a. Specifically, at time t2, the control unit 8 reduces (throttles) the aperture of the electronic expansion valve 24a to lower the temperature of the refrigerant flowing into the storage compartment heat exchanger 27a compared to the defrost control, and adjusts the aperture of the electronic expansion valve 24a so that the temperature of the refrigerant flowing into the storage compartment heat exchanger 27a becomes -10°C to -5°C.

[0059] In contrast to the time chart for explaining defrost control by control unit 8 in this embodiment shown in Fig. 6, Fig. 7 is a time chart for explaining defrost control in a comparative example. In the comparative example, when defrosting internal heat exchangers 27a to 27c, refrigerant expanded by electronic expansion valves 24a to 24c flows into internal heat exchangers 27a to 27c, and the openings of electronic expansion valves 24a to 24c are adjusted so that the temperature of the refrigerant flowing into internal heat exchangers 27a to 27c becomes the refrigerant temperature during defrosting. In contrast to the first embodiment, when defrosting the internal heat exchangers, operation of the compressors is stopped and refrigerant does not flow into the internal heat exchangers.

[0060] As shown in Fig. 7, the control unit according to the comparative example performs normal cooling operation to cool the right compartment by circulating refrigerant in the refrigerant circuit device from time t3 to time t4. Then, when the preset defrost control start time (time t4) arrives, the defrost control according to the comparative example is started. At time t4, the control unit stops the compressor. This stops the flow of refrigerant into the in-compartment heat exchanger. The control unit continues to drive the in-compartment fan even after time t4.

[0061] In the comparative example, at time t5, which is the same time as the time from time t1 to time t2 in the first embodiment, the temperature detected by the storage compartment temperature detection unit excessively exceeds the target product temperature. At time t5, the control unit stops the defrosting control according to the comparative example and resumes normal cooling control. The time p2 required for the temperature detected by the storage compartment temperature detection unit to fall to the target product temperature is longer than the time p1 required for the temperature detected by the storage compartment temperature detection unit 80a according to the first embodiment to fall to the target product temperature.

[0062] Therefore, in the vending machine 100 of this embodiment, by adjusting the aperture of the electronic expansion valve 24a so that the temperature of the refrigerant flowing into the internal heat exchanger 27a is 1°C, the temperature inside the right compartment 5a at time t2 can be made lower than the temperature inside the right compartment at time t5 in the comparative example. Also, in the vending machine 100 of this embodiment, the time p1 required for the temperature to drop to the target product temperature after normal cooling control is resumed can be made shorter than the time p2 required for the temperature to drop to the target product temperature in the comparative example.

[0063] (Effects of the first embodiment) In the first embodiment, the following effects can be obtained.

[0064] In the first embodiment, as described above, when defrosting the internal heat exchangers 27a to 27c, the control unit 8 controls the defrosting of the internal heat exchangers 27a to 27c by causing the refrigerant expanded by the electronic expansion valves 24a to 24c to flow into the internal heat exchangers 27a to 27c and adjusting the openings of the electronic expansion valves 24a to 24c so that the temperature of the refrigerant flowing into the internal heat exchangers 27a to 27c becomes a refrigerant temperature during defrosting that is higher than the temperature during cooling of the storage compartment 5. In this way, by causing the refrigerant having a refrigerant temperature during defrosting that is higher than the temperature during cooling of the storage compartment 5 to flow into the internal heat exchangers 27a to 27c, the air inside the storage compartment 5 can be cooled by evaporation of the refrigerant in the internal heat exchangers 27a to 27c while defrosting the internal heat exchangers 27a to 27c without stopping the refrigerant supply. Therefore, when the internal heat exchangers 27a to 27c are defrosted, the temperature inside the storage compartment 5 in which the products 105 are stored can be prevented from rising excessively.

[0065] Furthermore, in the first embodiment, as described above, the defrosting refrigerant temperature is higher than the cooling temperature in storage compartment 5 and lower than the target temperature in storage compartment 5, and control unit 8 is configured to perform defrosting control of internal heat exchangers 27a-27c by adjusting the openings of electronic expansion valves 24a-24c so that the temperature of the refrigerant flowing into internal heat exchangers 27a-27c becomes the defrosting refrigerant temperature during defrosting of internal heat exchangers 27a-27c. As a result, while defrosting of internal heat exchangers 27a-27c is being performed, the refrigerant having the defrosting refrigerant temperature during defrosting, which is higher than the cooling temperature in storage compartment 5 and lower than the target temperature in storage compartment 5, is evaporated in internal heat exchangers 27a-27c to cool the air in storage compartment 5, thereby making it possible to appropriately prevent the temperature in storage compartment 5 from becoming higher than the target temperature. Therefore, when the internal heat exchangers 27a to 27c are defrosted, the temperature inside the storage compartment 5 in which the products 105 are stored can be effectively prevented from rising excessively.

[0066] Furthermore, in the first embodiment, as described above, the defrosting refrigerant temperature is higher than 0°C and lower than the target temperature in storage compartment 5, and control unit 8 is configured to perform defrosting control of internal heat exchangers 27a-27c by adjusting the apertures of electronic expansion valves 24a-24c so that the temperature of the refrigerant flowing into internal heat exchangers 27a-27c becomes the defrosting refrigerant temperature during defrosting of internal heat exchangers 27a-27c. As a result, refrigerant having a defrosting refrigerant temperature higher than 0°C and lower than the target temperature in storage compartment 5 flows into internal heat exchangers 27a-27c, so that the air in storage compartment 5 is cooled by evaporation of the refrigerant in internal heat exchangers 27a-27c, while effectively defrosting internal heat exchangers 27a-27c, thereby appropriately preventing the temperature in storage compartment 5 from becoming higher than the target temperature. Therefore, when defrosting the internal heat exchangers 27a to 27c, it is possible to effectively defrost the internal heat exchangers 27a to 27c while appropriately preventing the temperature inside the storage compartment 5 in which the products 105 are stored from rising excessively.

[0067] Moreover, in the first embodiment, as described above, the refrigerator further includes internal fans 72a to 72c that send air to the internal heat exchangers 27a to 27c and send the air cooled in the internal heat exchangers 27a to 27c into the storage compartment 5, and the control unit 8 is configured to adjust the openings of the electronic expansion valves 24a to 24c when defrosting the internal heat exchangers 27a to 27c so that the temperature of the refrigerant flowing into the internal heat exchangers 27a to 27c becomes the refrigerant temperature during defrosting, and to perform defrost control of the internal heat exchangers 27a to 27c by sending air to the internal heat exchangers 27a to 27c using the internal fans 72a to 72c to melt frost adhering to the internal heat exchangers 27a to 27c. As a result, the internal fans 72a to 72c send air to the internal heat exchangers 27a to 27c to melt the frost that has adhered to the internal heat exchangers 27a to 27c, thereby efficiently defrosting the internal heat exchangers 27a to 27c. Therefore, when defrosting the internal heat exchangers 27a to 27c, the internal fans 72a to 72c efficiently defrost the internal heat exchangers 27a to 27c, thereby shortening the time required for defrosting the internal heat exchangers 27a to 27c, and thereby further preventing the temperature inside the storage compartment 5 where the products 105 are stored from rising excessively.

[0068] Furthermore, in the first embodiment, as described above, the control unit 8 further includes internal storage temperature detection units 80a-80c that detect the temperature inside the storage compartment 5, and the control unit 8 is configured to terminate defrost control of the internal storage heat exchangers 27a-27c when the temperature detected by the internal storage temperature detection units 80a-80c reaches a predetermined first defrost stop temperature that is higher than the target temperature inside the storage compartment 5 during defrosting of the internal storage heat exchangers 27a-27c, and adjust the apertures of the electronic expansion valves 24a-24c so that the temperature detected by the internal storage temperature detection units 80a-80c reaches the target temperature inside the storage compartment 5. This ensures that the time until the temperature detected by the internal storage temperature detection units 80a-80c reaches the first defrost stop temperature is available as the time for defrosting, and by terminating the defrost control of the internal storage heat exchangers 27a-27c when the first defrost stop temperature is reached, it is possible to further prevent the temperature inside the storage compartment 5 in which the products 105 are stored from rising excessively.

[0069] [Second embodiment] Next, a vending machine 200 (see FIG. 1) according to a second embodiment of the present invention will be described with reference to FIG. 8. Unlike the first embodiment described above in which defrost control (continuous cooling defrost) is terminated based on the temperature detected by the storage compartment temperature detection units 80a-80c reaching the first defrost stop temperature, the second embodiment will describe an example in which defrost control (continuous cooling defrost) is terminated based on the temperature detected by the first temperature detection units 81a-81c and the temperature detected by the storage compartment temperature detection units 80a-80c. Note that the same components as those in the first embodiment will be assigned the same reference numerals, and their description will be omitted.

[0070] When the temperature detected by the first temperature detection units 81a to 81c is equal to or higher than a predetermined second defrost stop temperature higher than 0°C and the temperature detected by the storage compartment temperature detection units 80a to 80c is decreasing during defrosting of each of the storage compartment heat exchangers 27a to 27c, the control unit 8 is configured to terminate the defrost control of the storage compartment heat exchangers 27a to 27c and adjust the openings of the electronic expansion valves 24a to 24c so that the temperatures detected by the storage compartment temperature detection units 80a to 80c become the target temperatures in the right compartment 5a, the middle compartment 5b, and the left compartment 5c.

[0071] In this embodiment, the second defrost stop temperature is, for example, 1°C. However, the second defrost stop temperature is not limited to 1°C. The second defrost stop temperature may be any temperature that is higher than 0°C and lower than the target product temperature of 5°C. In this embodiment, the target product temperature of the products 105 in the right storage 5a, middle storage 5b, and left storage 5c is, for example, 5°C, so the second defrost stop temperature may be 2°C or 4°C.

[0072] (Defrosting control of the internal heat exchanger by the control unit) Defrost control of internal heat exchangers 27a to 27c by control unit 8 will be described with reference to Figure 8. Defrost control of each of internal heat exchangers 27a to 27c is performed by control unit 8 using similar processing, so for ease of explanation, defrost control of internal heat exchanger 27a in CCC operation by control unit 8 will be described here. Note that in CCC operation, defrost control of internal heat exchangers 27a to 27c is performed by control unit 8, and in HCC operation, defrost control of internal heat exchangers 27a and 27b is performed by control unit 8.

[0073] Here, each of the internal heat exchangers 27a to 27c includes a plurality of fins (not shown). When the internal heat exchangers 27a to 27c are cooling the storage compartment 5, the fins may become clogged due to frost (ice) that forms between the fins included in the internal heat exchangers 27a to 27c. If the fins of the internal heat exchangers 27a to 27c are clogged, the air sent by the internal fans 72a to 72c does not flow between the fins, and the cooling performance of the air internal heat exchangers 27a to 27c decreases. Therefore, even during normal cooling operation in which the storage compartment 5 is cooled by circulating a refrigerant in the refrigerant circuit device 6, the temperature inside the storage compartment 5 may rise.

[0074] As shown in FIG. 8, from time t6 to time t7, normal cooling operation is performed to cool the right compartment 5a by circulating the refrigerant in the refrigerant circuit device 6. Specifically, normal cooling control by the control unit 8 switches the flow path switching valve 61 to the first delivery state, closes the electronic expansion valve 42, and opens the electronic expansion valve 24a. As a result, the refrigerant compressed by the compressor 21 flows sequentially through the flow path switching valve 61, the external heat exchanger 22, the electronic expansion valve 24a, the capillary 26a, and the internal heat exchanger 27a, and is then drawn into the compressor 21. The refrigerant is then compressed by the compressor 21, repeating the above-described circulation. The control unit 8 also drives the internal fan 72a to send air cooled by the internal heat exchanger 27a to the right compartment 5a.

[0075] Due to clogging of the fins of the internal heat exchanger 27a, the temperature inside the right-hand compartment 5a continues to rise even during normal cooling operation. The control unit 8 starts defrost control (continuous cooling defrosting) when a preset defrost control start time (time t7) arrives. In the example shown in FIG. 8, the temperature detected by the internal storage temperature detection unit 80a at the defrost control start time (time t7) has already exceeded the first defrost stop temperature (7°C) in the first embodiment.

[0076] At time t7, control unit 8 adjusts the aperture of electronic expansion valve 24a so that the temperature of the refrigerant flowing into internal heat exchanger 27a becomes the defrosting refrigerant temperature. Specifically, control unit 8 adjusts the aperture of electronic expansion valve 24a so that the temperature of the refrigerant flowing into internal heat exchanger 27a becomes 1°C. Furthermore, by continuously driving internal fan 72a, control unit 8 sends air cooled by internal heat exchanger 27a to right compartment 5a and performs defrost control of internal heat exchanger 27a while melting frost adhering to internal heat exchanger 27a and frost (ice) adhering between the fins with the air sent to internal heat exchanger 27a. At time t8, the temperature detected by first temperature detection unit 81a becomes the second defrost stop temperature (1°C).

[0077] While the fins of the internal heat exchanger 27a are clogged, the temperature detected by the internal storage temperature detection unit 80a continues to rise. However, when the frost (ice) adhering between the fins melts and the clogged fins of the internal heat exchanger 27a are cleared (time t9), the air is cooled by the internal heat exchanger 27a, and the temperature detected by the internal storage temperature detection unit 80a no longer rises. In other words, when the clogged fins of the internal heat exchanger 27a are cleared (time t9), the temperature detected by the internal storage temperature detection unit 80a remains constant or decreases. In the example shown in FIG. 8, the temperature detected by the internal storage temperature detection unit 80a decreases after time t9.

[0078] At time t10 when the temperature detected by first temperature detection unit 81a is equal to or higher than the second defrost stop temperature and the temperature detected by storage compartment temperature detection unit 80a is decreasing, control unit 8 stops defrost control (continuous cooling defrost) and resumes normal cooling control. Specifically, at time t10 when the temperature detected by first temperature detection unit 81a is equal to or higher than 1°C and the temperature detected by storage compartment temperature detection unit 80a has decreased by a predetermined temperature since time t9, control unit 8 ends the control for adjusting the aperture of electronic expansion valve 24a so that the temperature of the refrigerant flowing into storage compartment heat exchanger 27a becomes 1°C, and adjusts the aperture of electronic expansion valve 24a so that the temperature detected by storage compartment temperature detection unit 80a becomes the target temperature in right storage compartment 5a.

[0079] The other configurations of the second embodiment are the same as those of the first embodiment.

[0080] (Effects of the second embodiment) In the second embodiment, the following effects can be obtained.

[0081] As described above, the second embodiment further includes first temperature detection units 81a to 81c that detect the temperature of the refrigerant inlets of the internal heat exchangers 27a to 27c, and internal storage temperature detection units 80a to 80c that detect the temperature inside the storage compartment 5. The control unit 8 is configured to terminate the defrost control of the internal heat exchangers 27a to 27c when the temperature detected by the first temperature detection units 81a to 81c is equal to or higher than a predetermined second defrost stop temperature that is higher than 0°C and the temperature detected by the internal storage temperature detection units 80a to 80c is decreasing during defrosting of the internal storage heat exchangers 27a to 27c, and to adjust the openings of the electronic expansion valves 24a to 24c so that the temperature detected by the internal storage temperature detection units 80a to 80c becomes the target temperature inside the storage compartment. Here, if clogging occurs due to frost (ice) adhering between the fins of the internal heat exchangers 27a to 27c, the cooling capacity of the internal heat exchangers 27a to 27c will decrease. In this case, if the defrost control of the internal heat exchangers 27a to 27c is terminated without clearing the clogging of the internal heat exchangers 27a to 27c by defrosting the internal heat exchangers 27a to 27c, there is a possibility that the temperature inside the storage compartment 5 will rise rather than fall when cooling the storage compartment 5 after the defrost control of the internal heat exchangers 27a to 27c is terminated. Therefore, by configuring the defrost control of the internal heat exchangers 27a-27c to be terminated when the temperatures detected by the first temperature detection units 81a-81c are equal to or higher than the second defrost stop temperature and the temperatures detected by the internal storage temperature detection units 80a-80c are decreasing, it can be assumed that the internal heat exchangers 27a-27c are unclogged because the temperatures detected by the first temperature detection units 81a-81c are equal to or higher than the second defrost stop temperature and the temperatures detected by the internal storage temperature detection units 80a-80c are decreasing. In other words, it can be assumed that the defrosting of the internal heat exchangers 27a-27c is complete because the temperatures detected by the internal storage temperature detection units 80a-80c are decreasing. Therefore, it is possible to terminate the defrost control of the internal heat exchangers 27a-27c at an appropriate timing.

[0082] The other effects of the second embodiment are the same as those of the first embodiment.

[0083] [Third embodiment] Next, a vending machine 300 (see FIG. 1) according to a third embodiment of the present invention will be described with reference to Fig. 9. Unlike the first embodiment, in which defrost control (continuous cooling defrost) is terminated when the temperature detected by the storage compartment temperature detection units 80a-80c reaches the first defrost stop temperature, the third embodiment describes an example in which defrost control (continuous cooling defrost) is terminated based on the temperature detected by the first temperature detection units 81a-81c and the temperature detected by the second temperature detection units 82a-82c. Note that the same components as those in the first embodiment are designated by the same reference numerals, and their description will be omitted.

[0084] The internal heat exchanger 27a is provided with a second temperature detection unit 82a. The second temperature detection unit 82a is provided on the refrigerant pipe 28 near the refrigerant outlet of the internal heat exchanger 27a. The second temperature detection unit 82a is configured to detect the temperature near the refrigerant outlet of the internal heat exchanger 27a. The internal heat exchanger 27b is provided with a second temperature detection unit 82b. The second temperature detection unit 82b is provided on the refrigerant pipe 28 near the refrigerant outlet of the internal heat exchanger 27b. The second temperature detection unit 82b is configured to detect the temperature near the refrigerant outlet of the internal heat exchanger 27b. The internal heat exchanger 27c is provided with a second temperature detection unit 82c. The second temperature detection unit 82c is provided on the refrigerant pipe 28 near the refrigerant outlet of the internal heat exchanger 27c. The second temperature detection unit 82c is configured to detect the temperature near the refrigerant outlet of the internal heat exchanger 27c.

[0085] When the difference between the temperature detected by the first temperature detection units 81a to 81c and the temperature detected by the second temperature detection units 82a to 82c is equal to or greater than a predetermined temperature during defrosting of each of the internal heat exchangers 27a to 27c, the control unit 8 is configured to terminate the defrosting control of the internal heat exchangers 27a to 27c and adjust the openings of the electronic expansion valves 24a to 24c so that the temperatures detected by the internal storage temperature detection units 80a to 80c become the target temperatures in the right compartment 5a, the middle compartment 5b, and the left compartment 5c.

[0086] In this embodiment, the predetermined temperature is, for example, 1 K. However, the predetermined temperature is not limited to 1 K, and may be, for example, 0.5 K or 2 K.

[0087] (Defrosting control of the internal heat exchanger by the control unit) Defrost control of internal heat exchangers 27a to 27c by control unit 8 will be described with reference to Fig. 9. Defrost control of each of internal heat exchangers 27a to 27c is performed by control unit 8 using similar processing, so for ease of explanation, defrost control of internal heat exchanger 27a in CCC operation by control unit 8 will be described here. Note that in CCC operation, defrost control of internal heat exchangers 27a to 27c is performed by control unit 8, and in HCC operation, defrost control of internal heat exchangers 27a and 27b is performed by control unit 8.

[0088] Here, a difference between the temperature near the refrigerant inlet of internal heat exchanger 27a detected by first temperature detection unit 81a and the temperature near the refrigerant outlet of internal heat exchanger 27a detected by second temperature detection unit 82a means that the refrigerant temperature of the refrigerant flowing into internal heat exchanger 27a has risen above the saturation temperature (superheated), and heat exchange via the refrigerant is sufficient in internal heat exchanger 27a. In other words, when frost is attached to internal heat exchanger 27a, heat exchange is difficult in internal heat exchanger 27a, but the presence of a degree of superheat means that the frost attached to internal heat exchanger 27a has melted and defrosting is complete.

[0089] Therefore, when defrosting internal heat exchanger 27a, if the difference between the temperature detected by first temperature detection unit 81a and the temperature detected by second temperature detection unit 82a is 1 K or more, control unit 8 terminates defrost control of internal heat exchanger 27a. Control unit 8 terminates defrost control of internal heat exchanger 27a and adjusts the opening of electronic expansion valve 24a so that the temperature detected by internal storage temperature detection unit 80a becomes the target temperature inside right compartment 5a.

[0090] The other configurations of the third embodiment are the same as those of the first embodiment.

[0091] (Effects of the third embodiment) In the third embodiment, the following effects can be obtained.

[0092] As described above, the third embodiment further includes first temperature detection units 81a to 81c that detect the temperature of the refrigerant inlets of the internal heat exchangers 27a to 27c, second temperature detection units 82a to 82c that detect the temperature of the refrigerant outlets of the internal heat exchangers 27a to 27c, and internal storage temperature detection units 80a to 80c that detect the temperature inside the storage compartment, and the control unit 8 is configured to terminate the defrost control of the internal heat exchangers 27a to 27c when the difference between the temperature detected by the first temperature detection units 81a to 81c and the temperature detected by the second temperature detection units 82a to 82c is equal to or greater than a predetermined temperature during defrosting of the internal heat exchangers 27a to 27c, and to adjust the openings of the electronic expansion valves 24a to 24c so that the temperatures detected by the internal storage temperature detection units 80a to 80c become the target temperature inside the storage compartment 5. Here, a difference between the refrigerant inlet temperature detected by the first temperature detecting units 81a-81c and the refrigerant outlet temperature detected by the second temperature detecting units 82a-82c means that the refrigerant temperature of the refrigerant flowing into the internal heat exchangers 27a-27c has risen above the saturation temperature (superheated), and heat exchange via the refrigerant is sufficient in the internal heat exchangers 27a-27c. Therefore, by configuring the defrost control of the internal heat exchangers 27a-27c to end when the difference between the temperature detected by the first temperature detecting units 81a-81c and the temperature detected by the second temperature detecting units 82a-82c is equal to or greater than a predetermined temperature during defrosting of the internal heat exchangers 27a-27c, it can be estimated that the frost adhering to the internal heat exchangers 27a-27c has melted due to the presence of superheat, and that defrosting has been completed. Therefore, it is possible to accurately determine the completion of defrosting due to melting of frost adhering to the internal heat exchangers 27a to 27c, and therefore it is possible to end the defrosting control of the internal heat exchangers 27a to 27c at an appropriate timing.

[0093] The other effects of the third embodiment are the same as those of the first embodiment.

[0094] [Fourth embodiment] Next, with reference to FIGS. 10 to 12, a vending machine 400 (see FIG. 1) according to a fourth embodiment of the present invention will be described. Unlike the first embodiment, in which defrost control (continuous cooling defrosting) is started when the defrost control start time arrives and the defrost control (continuous cooling defrosting) is terminated when the temperature detected by the storage compartment temperature detection units 80a to 80c reaches a first defrost stop temperature, the fourth embodiment describes an example in which, at the start of defrosting, operation of the compressor 21 is stopped to perform cooling stop defrosting, which is different from defrosting performed by defrost control. Next, operation of the compressor 21 is started to start defrost control (continuous cooling defrosting), and the defrost control (continuous cooling defrosting) is terminated when the temperature detected by the first temperature detection units 81a to 81c reaches a fourth defrost stop temperature higher than 0°C. That is, in the fourth embodiment, cooling stop defrosting and continuous cooling defrosting are performed sequentially in defrosting the storage compartment heat exchangers 27a to 27c. Note that the same components as those in the first embodiment are designated by the same reference numerals, and their description will be omitted.

[0095] The control unit 8 is configured to perform cooling stop defrosting, which is different from defrosting by defrost control, by stopping the operation of the compressor 21 when defrosting of each of the internal heat exchangers 27a to 27c starts, and after the start of cooling stop defrosting, start the operation of the compressor 21 based on the temperature detected by the first temperature detection units 81a to 81c or the passage of a predetermined time, and after the start of operation of the compressor 21 after the start of cooling stop defrosting, adjust the opening of each of the electronic expansion valves 24a to 24c so that the temperature of the refrigerant flowing into the internal heat exchangers 27a to 27c becomes the refrigerant temperature during defrosting, thereby performing cooling continuous defrosting as defrosting by defrost control.

[0096] Specifically, the control unit 8 is configured to start operation of the compressor 21 when, after the start of cooling stop defrosting, the temperature detected by the first temperature detection units 81a to 81c becomes equal to or higher than the third defrost stop temperature, or when the above-mentioned predetermined time has elapsed.

[0097] In this embodiment, the third defrost stop temperature detected by the first temperature detection units 81a to 81c for starting the operation of the compressor 21 after the start of cooling stop defrosting is, for example, 7°C. The third defrost stop temperature is not limited to 7°C.

[0098] The predetermined time after the start of cooling-stop defrosting is, for example, 15 minutes. Note that the predetermined time after the start of cooling-stop defrosting is not limited to 15 minutes. The predetermined time after the start of cooling-stop defrosting may be shorter or longer than 15 minutes.

[0099] Furthermore, when the temperature detected by the first temperature detection units 81a to 81c reaches a fourth defrost stop temperature higher than 0°C during continuous cooling defrosting of each of the internal heat exchangers 27a to 27c, the control unit 8 is configured to terminate the defrost control of the internal heat exchangers 27a to 27c and adjust the openings of the electronic expansion valves 24a to 24c so that the temperatures detected by the internal storage temperature detection units 80a to 80c reach the target temperatures in the right compartment 5a, middle compartment 5b, and left compartment 5c.

[0100] In this embodiment, the fourth defrost stop temperature is, for example, 1°C. However, the fourth defrost stop temperature is not limited to 1°C. The fourth defrost stop temperature may be any temperature that is higher than 0°C and lower than the target product temperature of 5°C. In this embodiment, the target product temperature of the products 105 in the right storage 5a, middle storage 5b, and left storage 5c is, for example, 5°C, so the fourth defrost stop temperature may be 2°C or 4°C.

[0101] (Defrosting control of the internal heat exchanger by the control unit) 10 to 12, the defrost control of the internal heat exchangers 27a to 27c by the control unit 8 will be described. FIG. 10 is a time chart for explaining a first example of defrost control by the control unit 8 in a case where the temperatures detected by the first temperature detection units 81a to 81c become equal to or higher than the third defrost stop temperature before the predetermined time has elapsed after the start of cooling-stop defrosting. FIGS. 11 and 12 are time charts for explaining second and third examples of defrost control by the control unit 8 in a case where the temperatures detected by the first temperature detection units 81a to 81c become equal to or higher than the third defrost stop temperature after the start of cooling-stop defrosting. In the second example of FIG. 11, the vicinity of the refrigerant inlets of the internal heat exchangers 27a to 27c is frozen due to adhering frost (ice) at the start of cooling-stop defrosting. In the third example of FIG. 12, when cooling-stop defrosting starts, the areas near the refrigerant inlets of the internal heat exchangers 27a to 27c are not frozen due to the presence of frost (ice).

[0102] Note that the defrost control of each of the internal heat exchangers 27a to 27c is performed by the control unit 8 through similar processing, and therefore, for convenience of explanation, the following description will focus on the defrost control of the internal heat exchanger 27a in CCC operation by the control unit 8. Note that in CCC operation, the control unit 8 controls the defrosting of the internal heat exchangers 27a to 27c, and in HCC operation, the control unit 8 controls the defrosting of the internal heat exchangers 27a and 27b.

[0103] Referring to Figure 10, we will explain the defrost control by the control unit 8 when the temperature detected by the first temperature detection units 81a to 81c becomes equal to or higher than the third defrost stop temperature before the above-mentioned predetermined time has elapsed after the start of cooling stop defrosting.

[0104] As shown in FIG. 10, from time t14 to time t15, the refrigerant circuit device 6 circulates the refrigerant, thereby performing a normal cooling operation to cool the inside of the right compartment 5a.

[0105] When a preset defrost control start time (time t15) arrives, controller 8 starts cooling-stop defrosting, which differs from the defrost control (continuous cooling defrosting) in the first embodiment. Controller 8 stops the operation of compressor 21 at time t15. Controller 8 also sends air to right compartment 5a by continuously driving internal fan 72a. In other words, cooling-stop defrosting is defrosting in which, with the flow of refrigerant into internal heat exchanger 27a stopped, air is blown to internal heat exchanger 27a by internal fan 72a to melt frost that has adhered to internal heat exchanger 27a.

[0106] When the temperature detected by the first temperature detection unit 81a reaches the third defrost stop temperature, the control unit 8 ends the cooling-stop defrosting, starts operation of the compressor 21, and performs defrosting control (continuous cooling defrosting) similar to the defrosting control (continuous cooling defrosting) in the first embodiment. At time t16 when the temperature detected by the first temperature detection unit 81a reaches 7°C, the control unit 8 adjusts the aperture of the electronic expansion valve 24a so that the temperature of the refrigerant flowing into the internal heat exchanger 27a becomes the defrosting refrigerant temperature. Specifically, the control unit 8 adjusts the aperture of the electronic expansion valve 24a so that the temperature of the refrigerant flowing into the internal heat exchanger 27a becomes 1°C. The control unit 8 also continuously drives the internal fan 72a to send air cooled by the internal heat exchanger 27a to the right compartment 5a and perform defrosting control of the internal heat exchanger 27a while melting frost adhering to the internal heat exchanger 27a with the air sent to the internal heat exchanger 27a.

[0107] At time t17 when the temperature detected by first temperature detection unit 81a reaches the fourth defrost stop temperature, control unit 8 stops defrost control (continuous cooling defrost) and resumes normal cooling control. Specifically, at time t17 when the temperature detected by first temperature detection unit 81a reaches 1°C, control unit 8 ends the control for adjusting the aperture of electronic expansion valve 24a so that the temperature of the refrigerant flowing into in-compartment heat exchanger 27a reaches 1°C, and adjusts the aperture of electronic expansion valve 24a so that the temperature detected by in-compartment temperature detection unit 80a reaches the target temperature in right compartment 5a.

[0108] Next, referring to FIG. 11, the defrost control by the control unit 8 will be described in the case where, at the start of cooling-stop defrosting, the vicinity of the refrigerant inlets of the internal heat exchangers 27a to 27c is frozen due to adhering frost (ice), and after the start of cooling-stop defrosting, the above-mentioned predetermined time has elapsed before the temperatures detected by the first temperature detection units 81a to 81c become equal to or higher than the third defrost stop temperature.

[0109] As shown in FIG. 11, from time t18 to time t19, the refrigerant circuit device 6 circulates the refrigerant, thereby performing a normal cooling operation to cool the inside of the right compartment 5a.

[0110] When the preset defrost control start time (time t19) arrives, the control unit 8 starts cooling-stop defrosting, which differs from the defrost control (continuous cooling defrosting) in the first embodiment. At time t19, the control unit 8 stops the operation of the compressor 21. The control unit 8 also sends air to the right compartment 5a by continuously driving the internal fan 72a.

[0111] When a predetermined time has elapsed since the start of cooling-stop defrosting, control unit 8 ends the cooling-stop defrosting, starts operation of compressor 21, and performs defrosting control (cooling continuation defrosting) similar to the defrosting control (cooling continuation defrosting) in the first embodiment. At time t20, 15 minutes after the start of cooling-stop defrosting, control unit 8 adjusts the aperture of electronic expansion valve 24a so that the temperature of the refrigerant flowing into internal heat exchanger 27a becomes the defrosting refrigerant temperature. Specifically, control unit 8 adjusts the aperture of electronic expansion valve 24a so that the temperature of the refrigerant flowing into internal heat exchanger 27a becomes 1°C. Furthermore, control unit 8 continuously drives internal fan 72a to send air cooled by internal heat exchanger 27a to right compartment 5a, and performs defrosting control of internal heat exchanger 27a while melting frost adhering to internal heat exchanger 27a and frost (ice) adhering between the fins with the air sent to internal heat exchanger 27a.

[0112] At time t21 when the temperature detected by the first temperature detection unit 81a becomes the fourth defrost stop temperature, the control unit 8 stops the defrost control (continuous cooling defrost) and resumes normal cooling control.

[0113] Next, referring to FIG. 12, the defrost control by the control unit 8 will be described in the case where the vicinity of the refrigerant inlets of the internal heat exchangers 27a to 27c is not frozen due to the adhering frost (ice) at the start of the cooling stop defrosting, and the above-mentioned predetermined time has elapsed after the start of the cooling stop defrosting before the temperatures detected by the first temperature detection units 81a to 81c become equal to or higher than the third defrost stop temperature.

[0114] As shown in FIG. 12, from time t18 to time t19, the refrigerant circuit device 6 circulates the refrigerant, thereby performing a normal cooling operation to cool the inside of the right compartment 5a.

[0115] When the preset defrost control start time (time t19) arrives, the control unit 8 starts cooling-stop defrosting, which differs from the defrost control (continuous cooling defrosting) in the first embodiment. At time t19, the control unit 8 stops the operation of the compressor 21. The control unit 8 also sends air to the right compartment 5a by continuously driving the internal fan 72a.

[0116] When a predetermined time has elapsed since the start of cooling-stop defrosting, control unit 8 ends cooling-stop defrosting, starts operation of compressor 21, and performs defrosting control (cooling continuation defrosting) similar to the defrosting control (cooling continuation defrosting) in the first embodiment. At time t20, 15 minutes after the start of cooling-stop defrosting, control unit 8 adjusts the aperture of electronic expansion valve 24a so that the temperature of the refrigerant flowing into internal heat exchanger 27a becomes the defrosting time refrigerant temperature. Specifically, control unit 8 adjusts the aperture of electronic expansion valve 24a so that the temperature of the refrigerant flowing into internal heat exchanger 27a becomes 1°C. Furthermore, control unit 8 continuously drives internal fan 72a to send air cooled by internal heat exchanger 27a to right compartment 5a and perform defrosting control of internal heat exchanger 27a while melting frost adhering to internal heat exchanger 27a with the air sent to internal heat exchanger 27a.

[0117] At time t21 when the temperature detected by the first temperature detection unit 81a becomes the fourth defrost stop temperature, the control unit 8 stops the defrost control (continuous cooling defrost) and resumes normal cooling control.

[0118] The other configurations of the fourth embodiment are the same as those of the first embodiment.

[0119] (Effects of the fourth embodiment) In the fourth embodiment, the following effects can be obtained.

[0120] In the fourth embodiment, as described above, the control unit 8 further includes first temperature detection units 81a to 81c that detect the temperatures of the refrigerant at the inlet of the internal heat exchangers 27a to 27c, and the control unit 8 performs cooling stop defrosting, which is different from defrosting by defrost control, by stopping the operation of the compressor 21 when defrosting of the internal heat exchangers 27a to 27c starts, and after cooling stop defrosting starts, starts the operation of the compressor 21 based on the temperature detected by the first temperature detection units 81a to 81c or the passage of a predetermined time, and after the operation of the compressor 21 starts after the start of cooling stop defrosting, adjusts the pressure of the refrigerant to be discharged by the electronic expansion valves 24a to 24c so that the temperature of the refrigerant flowing into the internal heat exchangers 27a to 27c becomes the defrosting time refrigerant temperature, thereby performing cooling continuous defrosting as defrosting by defrost control. As a result, by performing cooling-stop defrosting at the start of defrosting of the internal heat exchangers 27a to 27c, the frost adhering to the internal heat exchangers 27a to 27c is melted by the heat of the refrigerant with an increased temperature, and by switching from cooling-stop defrosting to cooling-continuous defrosting based on the temperature detected by the first temperature detection units 81a to 81c or the passage of a predetermined time, it is possible to cause refrigerant at the defrosting time refrigerant temperature to flow into the internal heat exchangers 27a to 27c, thereby defrosting the internal heat exchangers 27a to 27c while cooling the storage compartment 5. Therefore, the defrosting time of the internal heat exchangers 27a to 27c can be shortened compared to when cooling-stop defrosting is not performed at the start of defrosting of the internal heat exchangers 27a to 27c.

[0121] Furthermore, in the fourth embodiment, as described above, the control unit 8 is configured to start operation of the compressor 21 after the start of cooling-stop defrosting when the temperature detected by the first temperature detection units 81a to 81c becomes equal to or higher than a preset third defrost stop temperature that is higher than the target temperature inside the storage compartment 5, or when a predetermined time has elapsed. As a result, when the temperature detected by the first temperature detection units 81a to 81c becomes equal to or higher than the third defrost stop temperature, the control unit 8 switches from cooling-stop defrosting to cooling-continue defrosting, thereby making it possible to further prevent the temperature inside the storage compartment 5 in which the products 105 are stored from rising excessively when the internal heat exchangers 27a to 27c are being defrosted.

[0122] The other effects of the fourth embodiment are the same as those of the first embodiment.

[0123] [Variations] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than the above description of the embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0124] For example, in the third embodiment described above, an example was shown in which second temperature detection unit 82a was provided on refrigerant pipe 28 near the refrigerant outlet of internal heat exchanger 27a, second temperature detection unit 82b was provided on refrigerant pipe 28 near the refrigerant outlet of internal heat exchanger 27b, and second temperature detection unit 82c was provided on refrigerant pipe 28 near the refrigerant outlet of internal heat exchanger 27c, but the present invention is not limited to this. For example, as in the first modified example, vending machine 500 may be configured to include, instead of second temperature detection units 82a to 82c, second temperature detection unit 82d provided on refrigerant pipe 28 at junction 90 where refrigerants flowing out from the refrigerant outlets of internal heat exchangers 27a to 27c join, between compressor 21.

[0125] 13, in the vending machine 500 according to the first modified example, the second temperature detection unit 82d is provided in the refrigerant piping 28 between the junction 90 where the refrigerants flowing out from the refrigerant outlets of the internal heat exchangers 27a to 27c join and the compressor 21. The second temperature detection unit 82d is configured to detect the temperature in the refrigerant piping 28 between the junction 90 and the compressor 21.

[0126] When the difference between the highest temperature among the temperatures detected by the first temperature detection units 81a to 81c and the temperature detected by the second temperature detection unit 82d is equal to or greater than a predetermined temperature during defrosting of the internal heat exchangers 27a to 27c, the control unit 8 is configured to terminate the defrosting control of the internal heat exchangers 27a to 27c and adjust the openings of the electronic expansion valves 24a to 24c so that the temperatures detected by the internal storage temperature detection units 80a to 80c become the target temperatures in the right compartment 5a, middle compartment 5b, and left compartment 5c, respectively.

[0127] In the first modified example as well, the predetermined temperature is, for example, 1 K. Note that the predetermined temperature is not limited to 1 K, and may be, for example, 0.5 K or 2 K.

[0128] (Defrosting control of the internal heat exchanger by the control unit) The defrosting control of the internal heat exchangers 27a to 27c by the control unit 8 will be described with reference to Fig. 13. For ease of explanation, the defrosting control of the internal heat exchangers 27a to 27c by the control unit 8 in CCC operation will be described here.

[0129] When defrosting the internal heat exchangers 27a-27c, the control unit 8 ends the defrost control of the internal heat exchangers 27a-27c if the difference between the highest temperature among the temperatures detected by the first temperature detection units 81a-81c and the temperature detected by the second temperature detection unit 82d is 1 K or more. The control unit 8 ends the defrost control of the internal heat exchangers 27a-27c and adjusts the apertures of the electronic expansion valves 24a-24c so that the temperatures detected by the internal storage temperature detection units 80a-80c become the target temperatures in the right compartment 5a, middle compartment 5b, and left compartment 5c, respectively.

[0130] The other configurations of the first modified example are the same as those of the third embodiment.

[0131] In the first modified example, as described above, when defrosting the internal heat exchangers 27a-27c, if the difference between the highest temperature among the temperatures detected by the first temperature detecting units 81a-81c and the temperature detected by the second temperature detecting unit 82d is 1 K or more, the openings of the electronic expansion valves 24a-24c are adjusted so that the temperatures detected by the internal temperature detecting units 80a-80c that terminate defrosting control for the internal heat exchangers 27a-27c become the target temperatures in the storage compartment 5. This allows for a reduction in the number of parts compared to when second temperature detecting units 82a-82c that detect the temperatures at the refrigerant outlets of the internal heat exchangers 27a-27c are provided. Note that other effects of the first modified example are similar to those of the third embodiment.

[0132] Furthermore, in the first to fourth embodiments and the first modified example, the control unit is configured to terminate the defrost control of the internal heat exchangers 27a to 27c based on different conditions, but the present invention is not limited to this. For example, the control unit may be configured to combine multiple conditions from among the conditions for terminating the defrost control in the first to fourth embodiments and the first modified example, and terminate the defrost control of the internal heat exchangers 27a to 27c when all of the combined conditions are satisfied.

[0133] In the second embodiment, the control unit is configured to terminate defrost control of the internal heat exchanger when the temperature detected by the first temperature detection unit is equal to or higher than the second defrost stop temperature and the temperature detected by the internal storage compartment temperature detection unit is decreasing during defrosting of the internal heat exchanger. However, the present invention is not limited to this. For example, the control unit may be configured to terminate defrost control of the internal heat exchanger when the temperature detected by the first temperature detection unit is equal to or higher than the second defrost stop temperature and the temperature detected by the internal storage compartment temperature detection unit is constant and not increasing during defrosting of the internal heat exchanger.

[0134] That is, the control unit may be configured to terminate defrost control of the internal heat exchanger when the temperature detected by the first temperature detection unit is equal to or higher than the defrost stop temperature and the temperature detected by the internal storage temperature detection unit is constant during defrosting of the internal storage heat exchanger, and adjust the aperture of the electronic expansion valve so that the temperature detected by the internal storage temperature detection unit becomes the target temperature inside the storage. As a result, it can be inferred that clogging of the internal storage heat exchanger has been eliminated even when the temperature detected by the first temperature detection unit is equal to or higher than the second defrost stop temperature and the temperature detected by the internal storage temperature detection unit is constant. That is, it can be inferred that defrosting of the internal storage heat exchanger has been completed when the temperature detected by the internal storage temperature detection unit is constant. Therefore, it is possible to suppress a rise in the temperature inside the storage compartment due to clogging caused by frost (ice) between the fins of the internal storage heat exchanger not being eliminated after the defrost control of the internal storage heat exchanger has been terminated.

[0135] In the first to fourth embodiments, the refrigerant temperature during defrosting is set to a value higher than 0°C and lower than the target temperature inside the storage compartment when the refrigerant flows into each of the internal heat exchangers, but the present invention is not limited to this. For example, the refrigerant temperature during defrosting may be any value higher than the temperature inside the storage compartment when the refrigerant is cooled.

[0136] In addition, in the first to fourth embodiments, an example was shown in which an internal fan was provided to send air to the internal heat exchanger and to send the air cooled by the internal heat exchanger into the storage compartment, but the present invention is not limited to this. For example, the vending machine does not need to be provided with an internal fan. [Explanation of symbols]

[0137] 5 Containment 8 Control Unit 21 Compressor 22 External heat exchanger (condenser) 24a, 24b, 24c Electronic expansion valve (expansion valve) 27a, 27b, 27c Internal heat exchanger (evaporator) 72a, 72b, 72c Indoor fan (blower) 80a, 80b, 80c Temperature detection unit inside storage 81a, 81b, 81c First temperature detection unit 82a, 82b, 82c Second temperature detection unit 100, 200, 300, 400, 500 vending machines

Claims

1. a storage facility for storing the goods; a compressor that compresses a refrigerant; a condenser that condenses the refrigerant discharged from the compressor; an expansion valve that expands the refrigerant condensed by the condenser; an evaporator that evaporates the refrigerant expanded by the expansion valve; a control unit that, when defrosting the evaporator, causes the refrigerant expanded by the expansion valve to flow into the evaporator, and adjusts the opening of the expansion valve so that the temperature of the refrigerant flowing into the evaporator becomes a refrigerant temperature during defrosting that is higher than the temperature during cooling in the storage compartment, thereby performing defrosting control of the evaporator.

2. The defrosting refrigerant temperature is higher than the temperature during cooling in the storage compartment and lower than the target temperature in the storage compartment, 2. The vending machine according to claim 1, wherein the control unit is configured to perform defrosting control of the evaporator by adjusting an opening degree of the expansion valve so that the temperature of the refrigerant flowing into the evaporator becomes the defrosting time refrigerant temperature during defrosting.

3. The defrosting refrigerant temperature is higher than 0°C and lower than the target temperature in the storage compartment, 3. The vending machine according to claim 2, wherein the control unit is configured to perform defrosting control of the evaporator by adjusting an opening degree of the expansion valve so that the temperature of the refrigerant flowing into the evaporator becomes the defrosting time refrigerant temperature during defrosting.

4. The cooling system further includes a blower that sends air to the evaporator and sends the air cooled by the evaporator into the storage compartment, 2. The vending machine according to claim 1, wherein the control unit is configured to adjust the opening of the expansion valve so that, when defrosting the evaporator, the temperature of the refrigerant flowing into the evaporator becomes the refrigerant temperature during defrosting, and to perform defrosting control of the evaporator while blowing air to the evaporator with the blower to melt frost adhering to the evaporator.

5. Further provided is a storage compartment temperature detection unit that detects the temperature inside the storage compartment, The vending machine according to any one of claims 1 to 3, wherein the control unit is configured to terminate defrost control of the evaporator when the temperature detected by the storage compartment temperature detection unit becomes a predetermined first defrost stop temperature that is higher than the target temperature in the storage compartment during defrosting of the evaporator, and to adjust the opening of the expansion valve so that the temperature detected by the storage compartment temperature detection unit becomes the target temperature in the storage compartment.

6. a first temperature detection unit that detects a temperature of a refrigerant inlet of the evaporator; Further provided is a storage compartment temperature detection unit that detects the temperature inside the storage compartment, The vending machine according to any one of claims 1 to 3, wherein the control unit is configured to terminate defrost control of the evaporator when the temperature detected by the first temperature detection unit is equal to or higher than a predetermined second defrost stop temperature higher than 0°C and the temperature detected by the storage compartment temperature detection unit is constant or decreasing, and to adjust the opening of the expansion valve so that the temperature detected by the storage compartment temperature detection unit becomes the target temperature inside the storage compartment.

7. a first temperature detection unit that detects a temperature of a refrigerant inlet of the evaporator; a second temperature detection unit that detects a temperature of a refrigerant outlet of the evaporator; Further provided is a storage compartment temperature detection unit that detects the temperature inside the storage compartment, The vending machine according to any one of claims 1 to 3, wherein the control unit is configured to terminate defrosting control of the evaporator when a difference between the temperature detected by the first temperature detection unit and the temperature detected by the second temperature detection unit is equal to or greater than a predetermined temperature during defrosting of the evaporator, and to adjust the opening of the expansion valve so that the temperature detected by the storage compartment temperature detection unit becomes a target temperature inside the storage compartment.

8. a first temperature detector for detecting a temperature of a refrigerant inlet of the evaporator; The control unit When defrosting of the evaporator starts, the operation of the compressor is stopped to perform cooling stop defrosting, which is different from defrosting by the defrosting control, After the cooling stop defrosting is started, the compressor is started to operate based on the temperature detected by the first temperature detection unit or the passage of a predetermined time. The vending machine according to any one of claims 1 to 3, wherein the vending machine is configured to perform continuous cooling defrosting as defrosting by the defrost control by adjusting the pressure of the refrigerant flowing out of the expansion valve so that the temperature of the refrigerant flowing into the evaporator becomes the refrigerant temperature during defrosting after operation of the compressor has started after the start of cooling stop defrosting.

9. The vending machine according to claim 8, wherein the control unit is configured to start operation of the compressor when, after the start of the cooling stop defrosting, the temperature detected by the first temperature detection unit becomes equal to or higher than a preset third defrost stop temperature that is higher than a target temperature in the storage compartment, or when the predetermined time has elapsed.

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