JPH0128872B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a refrigerated/heated storage for use in vending machines, show cases, etc., in which articles can be stored either cooled or warmed.

Conventional structure and its problems Conventionally, vending machines are generally known as this type of refrigerated/hot storage storage with switching operation. This will be explained with reference to the diagram. In the text, refrigeration is called cold, and heating is called warm.

1 is the main body of the vending machine consisting of an insulated box body 2;
The interior of the main body 1 is partitioned left and right into two product storage chambers 3a and 3b, and each chamber 3
Product shelves 4a and 4b are provided at a and 3b, respectively. The product shelves 4a and 4b may be serpentine type columns, so a detailed explanation will be omitted.

In addition, the product storage chambers 3a and 3b are provided with cooling evaporators 5a and 5b, and heating heaters 6, respectively.
Blower fans 7a and 7b are arranged to forcefully circulate cold air and warm air into the rooms 3a and 6b and the respective rooms 3a and 3b. Evaporators 5a and 5b arranged in each chamber 3a and 3b are connected in series to each other,
Electric compressor 8, capacitor 9, shunt 10, first
Capillary tube 11a, evaporator 5a,
The evaporators 5b are connected in sequence. Further, a second capillary tube 11b is provided that bypasses the evaporator 5a, and a refrigerant control valve 12 consisting of a reverse-acting electromagnetic valve is disposed at the inlet of the first capillary tube 11a. This refrigerant control valve 12 is a type of valve that closes when energized and opens when not energized. The refrigerant control valve 12 is opened and closed by an administrator manually operating a changeover switch 15 to select between cold and warm operation.

A fan motor 13 radiates heat from the electric compressor 8 and the condenser 9.

Next, the circuit will be explained.

The blowing fans 7a and 7b are each connected to a power source. Furthermore, the fan motor 13 and the electric compressor 8 are connected to a refrigerating thermostat (hereinafter referred to as thermostat) 1.
4 and a power supply via a changeover switch 16. Reference numeral 15 denotes a switch for setting the temperature and cooling of the chamber 3a, and when the switch 15 is turned on, the heater 6a for heating the right chamber and the refrigerant control valve 12 are energized.

Further, the heating heater 6b is connected to a power source via the other switch 16.

In the above configuration, the operation will be explained. When the product storage chambers 3a and 3b are both in cooling operation, the switch 15 is turned OFF, and the refrigerant control valve 12 and the heater 6a are turned off.
Open the circuit. Further, the electric compressor 8 and the fan motor 13 are connected to the power source by the changeover switch 16.
This activates the cooling system, and the liquid refrigerant condensed in the condenser 9 flows into the flow divider 10, where gas and liquid are separated. Then, the liquid refrigerant flows to the first capillary tube 11a connected to the lower outlet of the flow divider 10, and the gas refrigerant flows to the second capillary tube 11b. At this time, since the amount of refrigerant flowing into the second capillary tube 11b is extremely small compared to the first capillary tube 11a,
The refrigerant flow path flows as shown by the solid arrow. Then, the refrigerant sequentially flows through both evaporators 5a and 5b. As a result, both product storage chambers 3a and 3b are cooled until the cold thermostat 14 is turned off. In addition, the product storage room 3a
When operating the product storage compartment 3b to keep it warm and cool the product storage compartment 3b, turn on the switch 15 to turn on the refrigerant control valve 12,
The heater 6a is energized. However, the changeover switch 1
6 remains as described above.

As a result, the flow of the refrigerant from the flow divider 10 to the first capillary tube 11a is blocked by the refrigerant control valve 12. As a result, the flow divider 10
to the second capillary tube, evaporator 5b
As a result, the refrigerant circuit becomes a refrigerant circuit as shown by the dotted arrow in FIG. 2, and only the product storage chamber 3b is cooled.
The other product storage chamber 3a is heated by a heating heater 6a.

If both product storage chambers 3a and 3b are warm, switch the switch 16 to the circuit on the heating heater 6b side and turn on the switch 15.
Stop the electric compressor 8 and turn on the heating heaters 6a and 6b.
As a result, both product storage chambers 3a and 3b are heated. However, in the case of cold-to-hot operation, compared to the case of cold-cold operation, in order to perform gas-liquid separation of the refrigerant by the flow divider 10, the internal volume of the flow divider 10 must be increased, and the internal volume of the flow divider 10 must be increased. Sufficient gas-liquid separation could not be achieved unless the refrigerant flow rate was sufficiently reduced. Therefore, it was necessary to make the flow divider 10 very large, but during cold-temperature operation, liquid refrigerant accumulates in the flow divider 10, so the settings of each chamber 3a, 3b are changed from cold to cold to cold to cold. The amount of refrigerant will be different depending on the temperature. In addition, if the flow divider 10 is made smaller, the second capillary tube 11 can be used during cold-cold operation.
The liquid refrigerant tends to flow into the b side, making the cooling system unstable. Moreover,
The period of cold-warm operation is from late autumn to early spring when the outside temperature is low.
Since the amount of heat dissipated from the capacitor during the cooling cycle becomes large compared to the amount of cooling load, the capacitor 9
The refrigerant becomes supercooled within the tank. For this reason, a phenomenon occurs in which liquid refrigerant accumulates in the condenser 9, which further causes a shortage of refrigerant during cold-temperature operation, resulting in a drawback that the cooling system becomes unstable.

OBJECTS OF THE INVENTION It is an object of the present invention to eliminate the above-mentioned drawbacks and to obtain a cooling system that ensures stable cooling performance and heating performance during cold-to-hot operation.

Structure of the Invention In order to achieve this object, the number of revolutions of a fan motor for dissipating heat from a condenser in a cooling system is controlled in stages in accordance with changes in outside air temperature. This prevents excess or deficiency of the appropriate amount of refrigerant in the cooling system, thereby making the cooling system more stable.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. 4, but since the configuration of the cooling system is the same as the conventional one, a detailed explanation thereof will be omitted, and the different electric circuits will be explained in detail. do.

Reference numeral 17 is a changeover switch whose contacts 17a and 17b are activated by the operation of an outside temperature thermostat 18 which opens at a temperature below 10°C. The tap changeover switch 17 closes the contact 17a side when the coil 17c is energized. 19 is a variable speed fan motor provided with two terminals 19a and 19b having different winding resistances. Then, the coil 1 of the tap changeover switch 17 is turned on via the outside temperature thermostat 18.
7c is connected to a power source, and the high-speed side terminal 19a of the fan motor 19 is connected to the contact 17a, and the low-speed side terminal 19b is connected to the contact 17b. Further, the common end of the tap changeover switch 17 is connected to the power source via the cold thermostat 14 and the changeover switch 16.

In such a device, a case will be described in which each chamber 3a, 3b is operated in hot-cold mode, but since the flow of the refrigerant is the same as that explained in the conventional example, detailed explanation will be omitted. When the outside temperature is 10°C or more, the outside temperature thermostat 18 is closed, the coil 17c is energized, the contact of the tap changeover switch 17 becomes the terminal 17a, and the fan motor 19 is connected to the high speed side terminal 19a. The fan motor 19 rotates at high speed. Therefore, the amount of heat dissipated from the condenser 9 is increased to operate the cooling system normally.

Further, when the outside temperature is at a low temperature of 10° C. or lower, the outside temperature thermostat 18 is opened to cut off the current to the coil 17c, and the contact of the tap changeover switch 17 is switched to the terminal 17b. At this time, the fan motor 19
is connected to the low-speed side terminal 19b, so the fan motor 19 rotates at a low speed. Therefore, the amount of heat dissipated from the capacitor 9 is reduced and overcooling does not occur, so that it becomes difficult for invalid liquid refrigerant to accumulate in the capacitor 9. This increases the amount of refrigerant that circulates through the system, resulting in a system that does not run out of refrigerant even when the outside temperature is low.

As described above, fluctuations in the outside temperature are detected by the outside temperature thermostat 18, and the rotation speed of the fan motor 13 is set to high speed when the outside temperature is high.
By rotating at a low speed when the outside temperature is low, the heat dissipation capacity of the condenser 9 in the cooling cycle can be controlled, and it is possible to prevent liquid refrigerant from pooling due to overcooling of the condenser 9 at low outside temperatures. Moreover, by setting the rotation to a low level, fan input can be reduced and energy can be saved. As a result, stable cooling/warming performance can be obtained regardless of outside temperature fluctuations, and by simply switching the cold/hot switch 15, 16, the rooms 3a, 3b can be set to cold-cold, hot-cold, or hot-warm combinations. This allows a single vending machine to sell cold and hot products at the same time.

Note that the present invention is not limited to a vending machine, and similar effects can be obtained with any cooling system that has two evaporators and controls the inflow of refrigerant into either one of the evaporators.

Effects of the Invention As is clear from the above embodiments, the present invention has the advantage that by rotating the fan motor of the condenser of the cooling system at low speed when the outside temperature is low, supercooled liquid refrigerant does not accumulate in the condenser, and Since it is possible to prevent excess or deficiency of refrigerant due to load fluctuations caused by temperature fluctuations, more stable cooling and heating performance can be achieved.

[Brief explanation of drawings]

Figure 1 is a front view of a conventional refrigerating/warming switching vending machine, Figure 2 is a refrigerant circuit diagram of the cooling system in Figure 1, and Figure 3 is the cooling/warming electricity shown in Figure 1. Wiring diagram, FIG. 4 is an electrical wiring diagram for cooling and heating showing one embodiment of the present invention. 5a, 5b... Evaporator, 6a, 6b...
Warming heater, 10... Flow divider, 11a, 11b...
...First and second capillary tubes, 15 ... Switch, 16 ... Changeover switch, 17 ... Tap changeover switch, 18 ... Outside temperature thermostat, 1
9...Fan motor.

Claims (1)

[Claims] 1. Two storage chambers are formed in the main body, a cooling evaporator and a heating heater are respectively arranged in the two chambers, and a switch for switching between refrigeration and warming operation is provided and installed in the two chambers. A cooling system is formed by connecting the evaporators in series, an electric compressor, a condenser, a flow divider, a first capillary tube, an evaporator in one of the storage compartments, and an evaporator in the other storage compartment. A refrigerant control valve is connected between the system condenser and the first capillary tube, and a second capillary tube is provided at a position where the refrigerant is introduced from above the flow divider, and the other of the second capillary tubes is connected to the refrigerant control valve. A tap changeover switch connected between the two evaporators and configured to set multiple rotation speeds for the fan motor that radiates heat from the electric compressor and condenser; and an outside temperature thermostat that detects the outside temperature to switch the tap changeover switch. Refrigerated/hot storage storage connected in series.