JP4238342B2 - Vending machine cooling system - Google Patents

Description

  The present invention relates to a vending machine that cools or heats products such as beverages in containers such as cans, bottles, packs, and PET bottles for sale.

  Conventionally, as a cooling control device for this type of vending machine, refrigerant evaporating that is installed in each of a plurality of product storage chambers for storing products to be sold and evaporates a refrigerant to cool the products to generate cold heat. A compressor that pressurizes and compresses the refrigerant that has been evaporated by the refrigerant evaporator to a low pressure, a refrigerant condenser that cools the refrigerant that has been compressed by the compressor and that has become high temperature, A distributor that divides the flow into the condenser, a decompression device that is connected downstream of the distributor and decompresses the refrigerant that has been compressed by the compressor, and a series connection circuit of the evaporator and the decompression device in series. Solenoid valves connected to open and close the refrigerant flow path to the evaporator, and circulation air is generated by circulating the air in the product storage room in order to transmit the cold heat generated by the evaporator to the product. Do And a temperature sensor that outputs a temperature signal of a product storage chamber necessary for opening / closing the solenoid valve and operating / stopping the compressor in response to the temperature of the product. A control device is provided that receives an electrical signal and outputs a signal for opening / closing the solenoid valve and operating / stopping the compressor.

  The controller closes each solenoid valve when the temperature of each circulating air reaches an allowable lower limit value (for example, 4 ° C.), and each temperature of the circulating air reaches an allowable upper limit value (for example, 8 ° C.). Then, each of the solenoid valves is opened, and when all the solenoid valves are closed, the operation of the compressor is stopped, and when any of the solenoid valves is opened, the compressor is operated. Resume operation.

Also, when the compressor is in operation, if the difference between the highest product storage room temperature and any other product storage room temperature exceeds a preset allowable temperature difference (for example, 3 degrees), either A cooling device for closing the solenoid valve is known. (For example, Patent Document 1)
As a result, the temperature of any product storage room can be made substantially the same, and the amount of heat entering the product storage room from the outside air that is proportional to the temperature difference between the product storage room and the outside air can be stored in the product storage room. It can be almost the same as the chamber (and therefore has the least amount of intrusion heat), eliminating the consumption of extra energy and allowing energy savings.

In addition, the cooling operation mode of this type of vending machine is a mode in which product storage rooms are divided into multiple rooms (mostly three rooms) with heat insulating walls, and all three rooms are cooled according to seasonal demands. It is used by switching to a cooling / heating operation mode in which two chambers are cooled and one chamber is heated. During the year, one room is cooled and two rooms are heated in winter, two rooms are cooled and one room is heated in spring and autumn, and all three rooms are cooled in summer.
Japanese Patent Laid-Open No. 5-258164 (page 7, FIG. 8)

  However, under the condition that the outside air temperature is, for example, 30 ° C. or more, when the cooling operation is performed on the three product storage rooms at the same time, the load on the compressor increases and the current flowing through the compressor increases, In order to prevent overload, an overcurrent prevention device may work to stop the compressor. In order to prevent this, it is only necessary to select and use a compressor with a large capacity. However, since the cooling operation is performed in two or less rooms in the three seasons of autumn, winter and spring, unnecessary power consumption occurs in the compressor itself. It is not preferable in terms of energy saving and not preferable in terms of cost.

  The present invention has been made in view of the above points, and provides a cooling device for a vending machine that can perform a cooling operation without any trouble even when the outside air temperature is high and that can keep power consumption low. Objective.

In order to achieve the above object, a vending machine according to claim 1 of the present invention is installed in each of a plurality of product storage rooms for storing products to be sold and evaporates a refrigerant to cool the products. A refrigerant evaporator that generates cold heat, a compressor that is installed downstream of these refrigerant evaporators and that compresses and compresses the refrigerant evaporated by the refrigerant evaporator to a low pressure, and a refrigerant to each of the refrigerant evaporators A plurality of solenoid valves each capable of opening and closing the flow path, a temperature detection means provided for each product storage chamber for detecting the temperature in the product storage chamber, and the solenoid valve receiving a detection signal from these temperature detection means In the vending machine cooling device comprising control means for controlling the opening / closing of the compressor and the operation / stop of the compressor, the control means has an operation evaporator number determination unit for controlling the operation number of the evaporator, From the start of compressor operation Until constant time operating a small evaporator speed than installed evaporator, after the predetermined time it is characterized by operating the entire evaporator.

  According to the vending machine cooling device of the present invention, by limiting the number of evaporators that operate even under high outside air temperatures, the compressor can be overloaded without selectively using a large capacity compressor. This is effective in that the cooling operation can be performed stably.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, this invention is not limited by this embodiment.

FIGS Embodiment 1, there is shown an embodiment of a vending machine according to the present invention. 1 is a front view of the vending machine, FIG. 2 is a cross-sectional view of the vending machine, FIG. 3 is a refrigerant circuit, FIG. 4 is a control block diagram, and FIG. 5 is a flowchart of the main part of cooling control.

  1 and 2, reference numeral 1 denotes a main body cabinet of a vending machine that becomes a heat-insulating housing, 2 denotes a partition wall that partitions the product storage chamber 3 at the top of the main body cabinet into three product rooms 3A to 3C, and 4 denotes a product. The product stored in the product storage rack 5 suspended indoors is shown. Reference numerals 6 to 13 denote components of the cooling unit disposed on the lower side of the main body cabinet 1, and reference numeral 6 denotes an evaporator, which is arranged one by one corresponding to each of the commodity rooms 3A to 3C, and is indicated as 6A to 6C. , 7 is a condenser, 8 is a compressor, 9 is an accumulator for storing unevaporated liquid refrigerant, 10 is a cavity, and each component is connected by a refrigerant pipe 11. Further, 12 is an evaporator fan for blowing cold heat from the evaporator to the product room, 13 is a condenser fan for exhausting heat from the condenser, 14 is a heater for heating the product in the product room, and 15 is a product. The inside temperature sensor which detects indoor temperature is shown. Reference numeral 16 denotes a circulation duct that returns the air that has cooled / heated the product in the product room to the evaporator / heater, and 17 is a shooter that rolls and conveys the sold product to a product sales port 19 installed below the outer door 18. In order to send the cool air discharged from the evaporator to the product, a large number of holes are formed. Reference numeral 20 denotes an inner door that is made of a heat insulating material and prevents heat from flowing into and out of the outside air.

  FIG. 3 is a cooling circuit diagram shown together with the control circuit of the cooling device of the vending machine corresponding to FIGS. In FIG. 3, 21 is an electromagnetic valve for stopping the transfer of the liquid refrigerant from the condenser 7 to the evaporators 6A to 6C in the respective product chambers, indicated as 21A to 21C corresponding to the respective evaporators. The internal temperature sensor is also indicated as 15A to 15C. Reference numeral 100 denotes a control device that receives a temperature signal from the temperature sensors 15A to 15C and outputs a signal for opening / closing the electromagnetic valves 21A to 21C and operating / stopping the compressor 8. Reference numeral 110 denotes an operation mode setting switch for setting and inputting a combined operation mode of cooling or heating for each of the commodity rooms 3A to 3C to the control device 100. Reference numeral 81 denotes an overload prevention device that is built in the compressor 8 and stops the operation of the compressor 8 when an overcurrent flows through the compressor 8 or when the temperature of the compressor 8 rises excessively. The load prevention device 81 is set so that the compressor 8 automatically returns after a certain period of time has elapsed since the stop.

FIG. 4 is a control block diagram according to the control device 100. A determination unit and a command unit indicated by 101 to 104 are incorporated in the control device 100.
101 is an operation evaporator number determination unit for determining the number of evaporators to be operated, 102 is an electromagnetic valve switching change determination unit for determining whether to change opening / closing of the electromagnetic valve, and 103 is to change opening / closing of the electromagnetic valve An electromagnetic valve opening / closing change determination unit 104 for determining whether or not is an electromagnetic valve opening / closing change command unit for instructing an electromagnetic valve to be changed. More specifically, the operation evaporation number determination unit 101 detects the internal temperature as shown in Table 1 and operates if all internal temperatures in the cooling chamber are equal to or lower than the set temperature Ts (for example, 12 ° C. or lower). The number of evaporators is N1 (for example, 3), and if it is larger than Ts, the number of evaporators is reduced and set to N2 (for example, 2).

(Table 1)
Operation evaporator number judgment unit

Set chamber temperature Ts
Tk <Ts (setting value)
Tk> Ts

Number of operating evaporators N1
N2


As shown in Table 2, the solenoid valve switching change unit 102 detects the time from the previous change, and if it is shorter than the set interval time ts (for example, 1 hour), the state is continued without being changed. If so, raise a flag for change.

(Table 2)
Solenoid valve switching change determination unit (1)

Time since last change t <ts
t> ts

Change judgment Continue Change


Next, as shown in Table 3, the temperature difference between the respective product storage rooms is calculated, and if the temperature difference is smaller than ΔTs (for example, 5 ° C.), the state is continued without changing the solenoid valve, and ΔTs or more. If so, raise a flag for change.

(Table 3)
Solenoid valve switching change determination unit (2)

Temperature difference in the product storage room ΔTk <ΔTs
ΔTk> ΔTst

Change judgment Continue Change


As shown in Table 4, the electromagnetic valve opening / closing change determination unit 103 determines whether to change the electromagnetic valve opening / closing based on the results of the operation evaporation number determination and the electromagnetic valve switching change determination. If the operation evaporation number determination is N1 (three), the opening / closing change of the solenoid valve is not performed. If the operation evaporation number determination is N2 (two), the result of the electromagnetic valve switching change determination is referred to. If the solenoid valve switching change determination (1) is changed, the opening / closing of the solenoid valve is changed. If the solenoid valve switching change determination (1) is continued, the result of the solenoid valve switching change determination (2) is referred to, and the determination result If it is changed, the opening / closing of the solenoid valve is changed, and if it is continued, the opening / closing of the solenoid valve is continued.
In the case of the three-chamber operation, since N1 = 3 is always continued, the normal cooling operation may be performed without performing the solenoid valve opening / closing change determination process.

(Table 4)
Solenoid valve open / close judgment part

Number of operating evaporators
N1
N2

Solenoid valve switching change judgment (1)
−
Change
Continued

Solenoid valve switching change judgment (2)
−
−
Change
Continued

Solenoid valve opening / closing change judgment
Continued
Change
Change
Continued

In the solenoid valve opening / closing change command unit 104, if the change command flag is set by the solenoid valve opening / closing change determination unit 103, N2 = 2, so two solenoid valves in the cooling product chamber are opened in descending order of the inside temperature. Then, the solenoid valves of the remaining product rooms (in this case, the remaining one room) having a low internal temperature are closed.

  If N2 = 2 is set for the vending machines in the four rooms, open the two solenoid valves in the cooling product room in descending order of the inside temperature, and the remaining product rooms (in this case, the rest in the room temperature). Close the solenoid valve in room 2. Similarly, when N2 = 3 is set, the three solenoid valves in the cooling product room are opened in order of increasing inside temperature, and the remaining solenoid valves in the product room having the low inside temperature (in this case, the remaining one). Close.

In this configuration, the cooling control operation will be described with reference to the flowchart of FIG.
When the vending machine is turned on, the compressor starts operation (S1), counts the number of cooling chambers to be operated in the operation mode (S2), and if there are three or more (S2 branch Y), the inside of the cooling chamber The temperature is read (S3). If all of the read internal temperatures are not the first set temperature (for example, 12 ° C.), the operation evaporation number is set to N2 (S4 branch N), and the determination of the change of solenoid valve is performed (S5). In the determination of the operation evaporation number in S5, the change time from the previous time is compared as shown in Table 2 in the first step, and when the set interval time ts (for example, 1 hour) is exceeded, a flag is set in the change setting. In the second step, the change setting is flagged when the maximum internal temperature exceeds ΔTs as compared with the set internal temperature difference ΔTs (for example, 5 degrees). Next, the electromagnetic valve opening / closing changing unit in S6 makes a determination as shown in Table 4. If there is a change, the electromagnetic valve opening / closing changing commanding unit 104 uses the electromagnetic valve of the evaporator in the internal storage with the highest internal temperature. And the solenoid valve of the evaporator having the lowest internal temperature is closed (S7). If there is no change in S6, the process returns to the beginning and the same control loop is repeated. If the cooling chamber is 2 or less or a predetermined temperature or less in S2 and S4, the normal cooling operation is started. Specifically, the solenoid valve is closed when the chamber temperature in each of the three chambers reaches the allowable lower limit (4 ° C), and the solenoid valve is opened again when the chamber temperature rises to the allowable upper limit (8 ° C). The cooling operation is continued so that the product in the warehouse has a constant temperature. Alternatively, if the temperature difference between the three chambers exceeds 3 degrees, the cooling operation of the two chambers may be performed.

  Next, an example of the cooling operation that is operated in the case of three-chamber cooling is shown in the time chart of FIG. In the figure, at the start of operation, all the three rooms are at the same temperature, and one of the three rooms, for example, the solenoid valve 21A in the left product room 3A is closed, and the solenoid valve 21B in the middle product room 3B and the right product room 3C. , 21C is opened and the cooling operation is started. When the first set interval time t1 is reached, the internal temperature difference is determined in S5, the internal temperature difference between the left product room 3A and the right product room 3C becomes larger than the set internal temperature difference ΔTs, and the process goes to S7. Then, the electromagnetic valve 21A of the evaporator 6A of the internal storage 3A having the highest internal temperature is opened, the electromagnetic valve 21C of the evaporator 6C having the lowest internal temperature is closed, and the cooling operation is continued. When the next set interval elapsed time t2 is reached, the electromagnetic valve 21C of the evaporator 6C of the internal storage 3C having the highest internal temperature is opened, and the electromagnetic valve 21B of the evaporator 6B having the lowest internal temperature is opened. It is closed and the cooling operation is continued. Thereafter, the cooling control operation continues in the same manner, and when all the internal temperatures drop below the first set temperature at t4, the normal cooling control operation is started by branch Y in S4.

If such a cooling operation is performed, the compressor is operated with only two chambers as a load when the load is high and the ambient temperature is high, and the compressor can be stably operated without being stopped in an overload operation.
(Embodiment 2) FIG. 7 shows another embodiment of the vending machine according to the present invention, and is a flowchart of the main part of the cooling control. The difference from the first embodiment is S41, in which S41 is used to determine the operating time of the vending machine (operating time of the compressor) instead of S4 that determines whether or not the internal temperature setting is lower. In step S41, the number of evaporators to be operated is N2 (for example, two) until the compressor operation time t exceeds the set operation time tu, and when the compressor operation time t exceeds the set operation time tu, the evaporator Is set to N1 (for example, 3). Others are the same as those of the first embodiment, and those having the same configuration are denoted by the same reference numerals and description thereof is omitted.

  In this control method, an example of the operation is shown in the time chart of FIG. The operation is the same as that shown in FIG. 6 until the elapsed time t3. However, when the set time Ts is exceeded before t4, the solenoid valves are opened in all the three chambers and the normal cooling operation is started.

Therefore, the all-room cooling operation start time of the three rooms is fixed as compared with the first embodiment, and there is still a fear of starting the overload operation, but the three-room cooling operation is surely started, so the cooling time is more There is an effect that it can be shortened.
(Embodiment 3) FIG. 9 is a flowchart of the main part of the cooling control showing another embodiment of the vending machine according to the present invention. The difference from the first embodiment is Step S42, which is Step S42 for determining the internal temperature decrease rate instead of Step S4 for determining whether or not the internal temperature setting is lower. In step S42, the number of evaporators to be operated is N1 (for example, three) until the internal temperature decrease rate v exceeds the set decrease rate vs, and when the internal temperature decrease rate v exceeds the set operation time vs, the evaporator. Is set to N2 (for example, 2). Others are the same as those of the first embodiment, and those having the same configuration are denoted by the same reference numerals and description thereof is omitted. In such a control method, the rate of decrease in the internal temperature decreases as the internal temperature decreases. Therefore, if the rate of decrease in the internal temperature falls below the set value, it can be detected that the interior is sufficiently cooled and the cooling load decreases, so it is better to switch to the simultaneous operation of 3 rooms below the set value (branch S42). N1). As a result, the compressor can be prevented from being overloaded and stably operated.
(Embodiment 4) FIGS. 10 to 14 show another embodiment of the vending machine according to the present invention. FIG. 10 is a refrigerant circuit diagram, FIG. 11 is a control block diagram, and FIG. FIG. The difference from the first embodiment is that the temperature sensor 22 is attached to the condenser 7, and in the flowchart of FIG. It is the point made into the step which detects when the temperature of a condenser is detected instead of and becomes lower than preset condensation temperature Tcs, and is determined. In step S43, the number of evaporators to be operated is N1 (for example, three) until the condenser temperature Tc exceeds the set condensation temperature Tcs, and when the internal temperature drop rate v exceeds the set operation time vs, Set the number to N2 (for example, 2). Others are the same as those of the first embodiment, and those having the same configuration are denoted by the same reference numerals and description thereof is omitted.

  In such a control method, the temperature of the condenser is an index that can more accurately detect the overload situation of the compressor 8, and therefore, the time for operating the three chambers is longer than the method shown in the other embodiments. The compressor is used at the maximum load, and a shorter cooling time can achieve the desired cooling.

It is a front view of the vending machine which shows Embodiment 1-4 of the vending machine by this invention. It is a cross-sectional view of the vending machine which shows Embodiment 1-4 of the vending machine by this invention. It is a refrigerant circuit which shows Embodiment 1-3 of the vending machine by this invention. It is a control block diagram which shows Embodiment 1-3 of the vending machine by this invention. It is a flowchart of the principal part of the cooling control which shows Embodiment 1 of the vending machine by this invention. It is an example of the time chart of the cooling control which shows Embodiment 1 of the vending machine by this invention. It is a flowchart of the principal part of the cooling control which shows Embodiment 2 of the vending machine by this invention. It is an example of the time chart of the cooling control which shows Embodiment 2 of the vending machine by this invention. It is a flowchart of the principal part of the cooling control which shows Embodiment 3 of the vending machine by this invention. It is a refrigerant circuit which shows Embodiment 4 of the vending machine by this invention. It is a control block diagram which shows Embodiment 4 of the vending machine by this invention. It is a flowchart of the principal part of the cooling control which shows Embodiment 4 of the vending machine by this invention.

Explanation of symbols

3 Commodity Storage Room 4 Commodity 6 Evaporator 7 Condenser 8 Compressor 21 Solenoid Valve 81 Compressor Protection Device 100 Control Device 101 Operation Evaporator Number Determination Unit 102 Solenoid Valve Change Change Unit 103 Solenoid Valve Open / Close Change Determination Unit 104 Solenoid Valve Open / Close Change Command

Claims (1)

A refrigerant evaporator that is installed in each of a plurality of product storage chambers for storing products to be sold and generates cold by evaporating a refrigerant to cool the products;
A compressor that is installed downstream of these refrigerant evaporators and pressurizes and compresses the refrigerant that has been evaporated by the refrigerant evaporator to a low pressure;
A plurality of solenoid valves each capable of opening and closing the refrigerant flow path to each refrigerant evaporator;
Temperature detection means provided for each product storage chamber for detecting the temperature in the product storage chamber;
In the vending machine cooling apparatus provided with a control means for controlling the opening / closing of the solenoid valve and the operation / stop of the compressor in response to detection signals from these temperature detection means,
The control means, said has a run vaporizer count determination unit that controls the number of operating evaporators, until a predetermined time from the start operation of the compressor is operated with a small evaporator speed than installing the evaporator, the predetermined Vending machine cooling system characterized by operating all evaporators after time .

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