JP4013677B2 - Refrigerant cooling circuit and vending machine using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a refrigerant cooling circuit and a vending machine using the same.
[0002]
[Prior art]
A refrigerant cooling circuit for cooling the inside of a heat-insulated housing (for example, inside a vending machine) forms a refrigerant circulation path by connecting a compressor, a cooler, a throttle, and an evaporator, and a series of refrigeration A refrigerant is circulated by executing a cycle. As a refrigerant circulating in the refrigerant cooling circuit, an HFC refrigerant (hydrofluorocarbon) is generally used today. However, from the viewpoint of protecting the global environment, there is a demand for the development of a refrigerant that has less influence on the global environment. Therefore, recently, a refrigerant cooling circuit that uses carbon dioxide as a refrigerant that does not adversely affect the human body in terms of nonflammability, safety, non-corrosion, and less influence on the ozone layer has been developed. Yes.
[0003]
[Problems to be solved by the invention]
In general, the compressor constituting the refrigerant cooling circuit compresses the refrigerant using refrigeration oil having a predetermined viscosity. This refrigerating machine oil plays a role in preventing wear inside the compressor, leakage of refrigerant, and the like. For example, refrigerating machine oil used in a reciprocating compressor prevents the cylinder from being worn, and also prevents the refrigerant from leaking by closing the gap between the cylinder and the piston. However, it is difficult to completely seal the refrigeration oil inside the compressor due to the structure of the compressor, and the refrigeration oil slightly flows out of the compressor and circulates in the refrigerant circulation path.
[0004]
By the way, when the refrigerant cooling circuit starts to execute the refrigeration cycle (starts operation), the pressure and temperature at each of the compressor, cooler, throttle unit, and evaporator constituting the refrigerant cooling circuit are generally low. The viscosity of the refrigerating machine oil is in a high state. Therefore, the refrigerating machine oil circulating in the refrigerant circulation path is likely to be clogged at the throttle portion, and the refrigerant may not easily flow through the throttle portion.
[0005]
For example, at the start of operation of the refrigerant cooling circuit using HFC refrigerant, the refrigerant supplied from the evaporator to the compressor decreases, and the low pressure side of the refrigerant cooling circuit (from the output portion of the throttle portion to the input portion of the compressor) The refrigerant circulation path) may be unnecessarily lowered, which may adversely affect the compression operation of the compressor.
[0006]
Further, in the refrigerant cooling circuit using carbon dioxide as the refrigerant, the pressure in the refrigerant cooling circuit is higher than that in the case of using the HFC refrigerant (refrigerant circulation path from the compressor output part to the throttle input part). Both sides rise and the internal load (friction, etc.) of the compressor increases, and the possibility of damaging the compressor itself increases. For this reason, as the refrigerating machine oil of this compressor, one having a higher viscosity than the refrigerating machine oil in the case of the HFC refrigerant is used. That is, the refrigerating machine oil circulating in the refrigerant cooling circuit using carbon dioxide as a refrigerant is very likely to be clogged at the throttle portion at low temperatures. Therefore, at the start of operation of the refrigerant cooling circuit using carbon dioxide as the refrigerant, the pressure on the high pressure side of the refrigerant cooling circuit may increase more than necessary, and the compressor may stop the compression operation.
[0007]
SUMMARY OF THE INVENTION An object of the present invention is to provide a refrigerant cooling circuit that can execute a stable refrigeration cycle by preventing refrigerating machine oil from clogging at a throttle portion, and a vending machine using the refrigerant cooling circuit. .
[0008]
[Means for Solving the Problems]
The present invention has been created to solve the above problems.
First, the present invention includes a compressor that compresses a refrigerant, a radiator that dissipates the refrigerant supplied from the compressor, a throttle unit that adjusts the flow rate of the refrigerant supplied from the radiator, and the throttle unit. And an evaporator for evaporating the supplied refrigerant and returning it to the compressor. A throttle for increasing the flow rate of the refrigerant in the throttle unit for a predetermined time from the start of operation of the refrigerant cooling circuit. Part control means, the throttle part control means, The power frequency of the compressor and the opening of the throttle Depending on the flow rate of the refrigerant in the throttle And the predetermined time It is a refrigerant cooling circuit characterized by being adjustable. According to the refrigerant cooling circuit, by increasing the flow rate of the refrigerant in the throttle unit for a predetermined time from the start of operation of the refrigerant cooling circuit, the refrigeration oil flowing out from the compressor is prevented from clogging in the throttle unit, A stable refrigeration cycle can be executed.
[0009]
Moreover, the said heat radiator is good also as heat-radiating the refrigerant | coolant supplied from the said compressor in the state of a supercritical pressure. According to this, it is possible to execute a stable refrigeration cycle in the refrigerant cooling circuit in which the refrigerant dissipates heat at supercritical pressure.
[0010]
Further, the refrigerant may be carbon dioxide. According to this, from the viewpoint of protecting the global environment, it is possible to execute a stable refrigeration cycle using carbon dioxide expected as a refrigerant in the cooling refrigerant circuit.
[0011]
In addition, the aperture portion is According to the output of the diaphragm control means It may be an electronic expansion valve whose valve opening is adjusted. According to this, a stable refrigeration cycle can be executed by using an electronic expansion valve whose valve opening is appropriately adjusted.
[0012]
The predetermined time may be determined according to the viscosity of the refrigerating machine oil for the compressor. According to this, since the flow rate of the refrigerant in the throttling portion increases only for a time corresponding to the viscosity of the refrigerating machine oil, it is possible to effectively prevent the refrigerating machine oil from being clogged in the throttling section and to execute a stable refrigerating cycle. It becomes possible.
[0013]
Furthermore, a compressor that compresses the refrigerant, a radiator that dissipates the refrigerant supplied from the compressor, a throttle unit that adjusts the flow rate of the refrigerant supplied from the radiator, and a refrigerant that is supplied from the throttle unit And an evaporator for evaporating and returning to the compressor, the refrigerant cooling circuit increases the flow rate of the refrigerant at the throttle portion for a predetermined time from the start of operation. A diaphragm control means for making the diaphragm control means, The power frequency of the compressor and the opening of the throttle Depending on the flow rate of the refrigerant in the throttle And the predetermined time It is also possible to realize a vending machine characterized by the fact that it can be adjusted.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
=== Configuration of Refrigerant Cooling Circuit ===
First, a configuration example of the refrigerant cooling circuit of the present invention will be described with reference to FIG. FIG. 1 is a diagram showing an embodiment of the refrigerant cooling circuit of the present invention. For example, carbon dioxide is used as the refrigerant.
[0015]
The refrigerant cooling circuit combines a compressor 2, a gas cooler (heat radiator) 4, an electronic expansion valve (throttle part) 6, and an evaporator 8 to form a refrigerant circulation path through which carbon dioxide can be circulated as a refrigerant. is there.
[0016]
The compressor 2 compresses the carbon dioxide supplied from the evaporator 8 to bring it into a high temperature and high pressure state. The temperature of the periphery of the evaporator 8 is lowered by the evaporator 8 absorbing the heat of the periphery. As a refrigeration cycle, it is necessary to throw away the heat of evaporation absorbed by the evaporator 8, but the inside of the heat insulating housing around the evaporator 8 is considerably lower than the outside temperature, and is taken away from the low temperature part. Heat cannot be thrown away directly to the hot outside. Therefore, the compressor 2 plays the role of converting carbon dioxide supplied from the evaporator 8 into high-temperature and high-pressure steam in order to discard the evaporation heat of the evaporator 8 at a temperature higher than the outside air temperature.
[0017]
Moreover, the compressor 2 is using the intermediate heat exchanger 10 for improving compression efficiency in this embodiment. The intermediate heat exchanger 10 cools the carbon dioxide once compressed by the compressor 2 and returns it to the compressor 2. Thereby, since the compressor 2 performs a two-stage compression operation, it is possible to obtain high compression efficiency with low power consumption. In addition, as a heat exchange medium of the intermediate heat exchanger 10, a medium that can effectively cool the compression heat of carbon dioxide can be appropriately applied. Further, the intermediate heat exchanger 10 can be omitted depending on the specifications of the compressor 2.
[0018]
The compressor 2 includes a reciprocating compressor, a rotary compressor, a scroll compressor, or an inverter compressor that can adjust the compression capacity thereof. A compressor corresponding to the cost of the refrigerant cooling circuit and the like can be applied as appropriate.
[0019]
The gas cooler 4 is for radiating the high-temperature and high-pressure carbon dioxide supplied from the compressor 2. By the way, in the summertime when the outside air temperature is high, when the temperature of the gas cooler 4 exceeds the critical temperature of carbon dioxide (about 31 ° C.), the carbon dioxide is vaporized and does not liquefy. Become. Therefore, an internal heat exchanger 12 is provided between the gas cooler 4 and the electronic expansion valve 6 and between the evaporator 8 and the compressor 2. Inside the internal heat exchanger 12, the refrigerant line between the gas cooler 4 and the electronic expansion valve 6 and the refrigerant line between the evaporator 8 and the compressor 2 have a distance at which heat exchange is possible. It arrange | positions so that non-contact countercurrent may flow. Thereby, the carbon dioxide obtained from the gas cooler 4 becomes easy to liquefy.
[0020]
The electronic expansion valve 6 performs pressure reduction until the temperature of carbon dioxide supplied from the gas cooler 4 via the internal heat exchanger 12 reaches the evaporation temperature of the evaporator 8. The electronic expansion valve 6 has a valve for adjusting the pressure of carbon dioxide supplied to the evaporator 8. That is, in the electronic expansion valve 6, when the valve opening degree is increased, the resistance when carbon dioxide passes is reduced, while when the valve opening degree is reduced, the resistance when carbon dioxide is passed is increased. In addition, as a method of adjusting the valve opening degree of the electronic expansion valve 6, there are an electromagnetic proportional method using an electromagnetic force, an electromagnetic duty method, a stepping motor driving method using a rotation amount of a motor, and the like. A method corresponding to the object to be disposed, the environment, the cost of the refrigerant cooling circuit, and the like can be appropriately applied. In this embodiment, the above stepping motor driving method is adopted.
[0021]
The stepping motor 14 rotates in step units (one step rotation angle θ), and adjusts the valve opening degree of the electronic expansion valve 6 by supplying a control signal A in pulse units from a control unit (described later). To do.
[0022]
The evaporator 8 is for cooling the ambient temperature by absorbing ambient heat when the liquid carbon dioxide supplied from the electronic expansion valve 6 evaporates. It is desirable that all the carbon dioxide that has passed through the evaporator 8 is vaporized. However, if the carbon dioxide that has passed through the evaporator 8 is supplied to the compressor 2 while being partially liquefied, the compressor 2 may cause liquid compression and break the cylinder. Therefore, in the internal heat exchanger 12, the carbon dioxide from the gas cooler 4 and the evaporator 8 exchanges heat by non-contact countercurrent. Thereby, the carbon dioxide vaporized from the internal heat exchanger 12 is supplied to the compressor 2. The internal heat exchanger may be provided independently between the gas cooler 4 and the electronic expansion valve 6 and between the evaporator 8 and the compressor 2. An internal heat exchanger between the gas cooler 4 and the electronic expansion valve 6 applies a dedicated heat exchange medium for liquefying carbon dioxide, and an internal space between the evaporator 8 and the compressor 2 is used. If the heat exchanger applies a dedicated heat exchange medium for vaporizing carbon dioxide, excellent heat exchange can be performed.
[0023]
The control unit 18 (throttle control unit) associates a timer 20 for measuring a predetermined time from the start of operation of the refrigerant cooling circuit, the valve opening of the electronic expansion valve 6 and the set time of the valve opening. The table 22 is provided. And the control part 18 outputs the control signal A for driving the stepping motor 14 based on the reference data of the table 22, and the time-measurement output of the timer 20. FIG. More specifically, the timer 20 is reset when the refrigerant cooling circuit is turned on (when the refrigerant cooling circuit starts operating), and starts measuring the set time stored in the table 22. In the control unit 18, when the timer 20 starts measuring the set time, the valve opening of the electronic expansion valve 6 is set to the valve opening stored in the table 22, and the timer 20 measures the set time. Is completed, a control signal A for returning the valve opening of the electronic expansion valve 6 to the initial opening is generated and output. As a result, the opening degree of the electronic expansion valve 6 is set larger than the initial opening degree for a predetermined time from the start of operation of the refrigerant cooling circuit.
[0024]
=== Relationship between Control Signal A and Valve Opening of Electronic Expansion Valve 6 ===
Next, the relationship between the control signal A and the valve opening degree of the electronic expansion valve 6 will be described with reference to FIG. FIG. 2 is an example of a characteristic diagram showing the relationship between the control signal A (horizontal axis) and the amount of carbon dioxide flowing through the electronic expansion valve 6 (vertical axis). For example, when the control signal A of 100 pulses is generated, the stepping motor 14 rotates 100 steps, and the electronic expansion valve 6 is adjusted to a valve opening at which carbon dioxide can flow out by 1.5 liters / minute. In addition, the normal valve opening degree of the electronic expansion valve 6 is set to a valve opening degree at which, for example, carbon dioxide can flow out at 1.5 liters / minute.
[0025]
=== Relationship between carbon dioxide mixing ratio of refrigerating machine oil and pressure ===
Next, the relationship between the carbon dioxide mixing ratio of the refrigerating machine oil used by the compressor 2 and the pressure will be described with reference to FIG. FIG. 3 is an example of a characteristic diagram showing the relationship between the carbon dioxide mixing ratio (horizontal axis) and the pressure (vertical axis) of the refrigerating machine oil. FIG. 3 is a characteristic diagram of one refrigerating machine oil (Daphne Hermetic Oil (registered trademark)) that is suitable when the compressor 2 compresses carbon dioxide as a refrigerant. The temperature (° C.), the carbon dioxide mixing ratio (wt) %) And pressure (MPa) are values where refrigeration oil and carbon dioxide are present in the refrigerant cooling circuit. Referring to FIG. 3, under the condition where the temperature is constant, the carbon dioxide mixing ratio indicating the ratio of the weight of carbon dioxide dissolved in the refrigerating machine oil (unit volume) increases as the pressure increases. Further, under the condition where the pressure is constant, the carbon dioxide mixing ratio increases as the temperature decreases. That is, as the pressure increases and the temperature decreases, carbon dioxide has a characteristic that it is more easily dissolved in the refrigerating machine oil.
[0026]
At the initial stage when the refrigerant cooling circuit of FIG. 1 starts operation, both the temperature and pressure are low. However, the pressure on the input side of the electronic expansion valve 6, that is, the pressure on the high pressure side of the compressor 2 is several MPa even if it is low, so that a considerable amount of carbon dioxide is dissolved in the refrigerating machine oil. Therefore, since a part of the refrigeration oil for the compressor 2 is supplied to the electronic expansion valve 6 together with carbon dioxide, the valve opening degree of the electronic expansion valve 6 is set large for a predetermined time from the start of operation of the refrigerant cooling circuit. There is a need.
[0027]
=== Relationship between temperature and viscosity of refrigerating machine oil ===
Next, the relationship between the temperature and the viscosity of the refrigerating machine oil used by the compressor 2 will be described with reference to FIG. FIG. 4 is an example of a characteristic diagram showing the relationship between the temperature (horizontal axis) and the viscosity (vertical axis) of the refrigerating machine oil. 4 is a characteristic diagram of one refrigerating machine oil (Daphne Hermetic Oil (registered trademark)) that is suitable when the compressor 2 compresses carbon dioxide as a refrigerant, similarly to FIG. The carbon dioxide mixing ratio (wt%) and the viscosity (mm 2 (square millimeter) / s) are values where the refrigerating machine oil and carbon dioxide exist in the refrigerant cooling circuit. Referring to FIG. 4, under the condition of a constant temperature, the viscosity of the refrigerating machine oil increases with a decrease in the carbon dioxide mixing rate. Further, under the condition where the carbon dioxide mixing ratio is constant, the viscosity of the refrigerating machine oil increases as the temperature decreases. Therefore, the refrigerating machine oil has a characteristic that the lower the carbon dioxide mixing rate and the lower the temperature, the more viscous the refrigerating machine oil.
[0028]
When the refrigerant cooling circuit of FIG. 1 starts operation, both the carbon dioxide mixing ratio and temperature are low. Therefore, a part of the refrigeration oil for the compressor 2 is supplied to the electronic expansion valve 6 in a state of high viscosity, so that the valve opening degree of the electronic expansion valve 6 needs to be set large.
[0029]
Therefore, it is necessary to set the valve opening of the electronic expansion valve 6 to be larger than the initial opening for the time corresponding to the viscosity of the refrigerating machine oil from the start of the operation of the refrigerant cooling circuit. I understand.
[0030]
=== Example of Table 22 of Control Unit 18 ===
The valve opening of the electronic expansion valve 6 and the set time when the valve opening of the electronic expansion valve 6 is made larger than the initial opening are the viscosity of the refrigerating machine oil that the compressor 2 has and the refrigerant circulating in the refrigerant cooling circuit. It is desirable that the value be in accordance with the type, the configuration of the refrigerant cooling circuit, the ambient temperature of the refrigerant cooling circuit, and the like. Therefore, the applicant of the present application conducted an experiment under the following conditions in order to prevent the refrigerating machine oil from clogging the electronic expansion valve 6. More specifically, refrigeration oil: “Daphne Hermetic Oil (registered trademark)”, refrigerant: “carbon dioxide”, compressor 2: “excluded volume is set in a range of 1 to 2 cc, and power supply frequency is set in a range of 50 to 60 Hz. When the operation is performed using the “inverter compressor”, when the electronic expansion valve 6 is set to a valve opening corresponding to 240 step rotation of the stepping motor 14 for 1 to 2 minutes from the time when the refrigerant cooling circuit starts operation. It has been found that clogging of refrigerating machine oil into the electronic expansion valve 6 can be effectively prevented. Therefore, data of “240 pulses” as the valve opening degree of the electronic expansion valve 6 and “2 minutes” as the set time of the valve opening degree are stored in the table 22 in advance. Further, the table 22 also stores data corresponding to other power supply frequencies in advance.
[0031]
Note that a temperature sensor (not shown) for detecting the ambient temperature of the refrigerant cooling circuit is provided, and the valve opening degree and set time of the electronic expansion valve 6 corresponding to the temperature detected by the temperature sensor when the refrigerant cooling circuit starts operation. It is good also as providing the table which can refer to.
[0032]
=== Operation of Refrigerant Cooling Circuit ===
Next, the operation of the refrigerant cooling circuit of the present invention using carbon dioxide as a refrigerant will be described with reference to FIGS. FIG. 5 is an example of a flowchart for explaining the operation of the refrigerant cooling circuit of the present invention. In the refrigerant cooling circuit of the present invention, for convenience of explanation, refrigeration oil: “Daphne Hermetic Oil (registered trademark)”, refrigerant: “carbon dioxide”, compressor 2: “excluded volume is in the range of 1 to 2 cc and power frequency. Is operated under the condition of “inverter compressor set in the range of 50 to 60 Hz”.
[0033]
First, when the power of the refrigerant cooling circuit is turned on (S2), the control unit 18 reads information on the power supply frequency of the compressor 2 and information on the number of rotation steps of the stepping motor 14. The control unit 18 has a memory 24 for storing information on the power supply frequency of the compressor 2 and information on the number of rotation steps of the stepping motor 14. For example, between the compressor 2 and the control unit 18, after setting the power supply frequency of the compressor 2, a control sequence in which information on the power supply frequency of the compressor 2 is supplied to the control unit 18 may be executed. After supplying the power frequency information of the compressor 2 to the control unit 18, a control sequence for setting the power frequency of the compressor 2 may be executed, or the power frequency information of the compressor 2 may be transmitted to the control unit 18. It is good also as supplying only. Therefore, the control unit 18 reads the power frequency information “50-60 Hz” of the compressor 2 and the information “100 pulses” of the number of rotations of the stepping motor 14 from the memory 24, and the power frequency information “50” of the compressor 2. Data “240 pulses” and “2 minutes” in the table 22 corresponding to “˜60 Hz” are extracted (S4).
[0034]
Then, the control unit 18 resets the timer 20, and the timer 20 starts measuring the set time “2 minutes” (S6).
[0035]
In the control unit 18, when the timer 20 starts measuring the set time “2 minutes”, the control signal A of 240 pulses is supplied to the stepping motor 14. Since the stepping motor 14 is set in a state where it has rotated 100 steps in the initial state, the stepping motor 14 rotates in the difference of 140 steps in response to the control signal A. Thereby, the valve opening degree of the electronic expansion valve 6 is set to a size that allows carbon dioxide to flow out by 4 liters / minute (S8).
[0036]
Further, in the control unit 18, whether or not the timer 20 has finished measuring the set time “2 minutes” in a state where the opening degree of the electronic expansion valve 6 is set to a size capable of flowing carbon dioxide at 4 liters / minute. Is discriminated (S10). When the control unit 18 determines that the timer 20 has not finished the set time “2 minutes” (S10: NO), the determination process of step S10 is executed again. On the other hand, in the control unit 18, when it is determined that the timer 20 has finished the set time “2 minutes” (S <b> 10: YES), the control signal A of 100 pulses is supplied to the stepping motor 14. Since the stepping motor 14 has been changed to a state where it has rotated 240 steps, in response to the control signal A at this time, the stepping motor 14 rotates in the reverse direction of the difference of 140 steps. Thereby, the valve opening degree of the electronic expansion valve 6 returns to the original magnitude | size which can flow out a carbon dioxide 1.5 liter / min (S12).
[0037]
As described above, the opening degree of the electronic expansion valve 6 increases from 1.5 liters / minute to 4 liters / minute for 2 minutes after the refrigerant cooling circuit starts operation. It can be effectively prevented.
[0038]
Note that the flowchart of FIG. 5 is an example for facilitating understanding of the present invention, and does not limit the present invention.
[0039]
=== Vending machine configuration ===
Next, an example of a vending machine using the refrigerant cooling circuit of the present invention will be described with reference to FIG. FIG. 6 is a diagram showing an example of the front surface of the vending machine according to the present invention. For example, a can beverage is sold.
[0040]
In FIG. 6, the front door 102 opens and closes using either the left or right side end of the vending machine as a support shaft, and is unlocked when setting a column for associating a product selection button with a column, refilling a can beverage, or the like. It is opened and locked for normal sales. The panel 104 is a transparent resin plate for confirming a plurality of types of can drink samples 106 displayed inside.
[0041]
That is, the user can select a can beverage to be purchased by looking over a plurality of types of can beverage samples 106 through the panel 104. The coin insertion slot 108 is a part where a user inserts coins, and the inserted coins are supplied to a coin identification device inside the vending machine. The bill insertion slot 110 is a portion into which a user inserts a bill, and the inserted bill is supplied to a bill recognition device inside the vending machine. The display unit 112 displays the column number in accordance with the operation of the remote controller 114 that is detachable on the back side of the front door 102 when setting the column, and indicates the amount of coins inserted, the amount of bills inserted, etc. To display. The display unit 112 can be configured using a display element such as an organic EL, LCD, or LED. The merchandise selection button 116 incorporates a sellable lamp 118 and a sold-out lamp 120, and is provided on the front side of the panel 104 corresponding to each can beverage sample 106. When the user inserts coins or inserts banknotes that allow the user to purchase at least one can drink, the sale ready lamp 118 corresponds to the can drink only when the can drink is stored in a column inside the vending machine. Things light up. As for the sold-out lamp 120, when a predetermined column in the vending machine becomes empty, the one corresponding to the can beverage is always lit. The display plate 122 is provided on the front side or the back side of the panel 104 corresponding to each of the product selection buttons 116, and information regarding canned beverages (characters “HOT” indicating that it is a heated beverage and cooling) when performing normal sales. Characters “COLD” representing beverages are displayed by color. The display plate 122 is a transmissive resin panel. The selling lamp 124 lights up when the can beverage is normally sold. The sales stop lamp 126 is lit when all the can beverages are sold out or when a sales mechanism for selling can beverages breaks down. The change change lamp 128 is turned on when the total amount of change coins in the coin identification device is equal to or less than a predetermined amount. When the product selection button 116 with the sale ready lamp 118 lit is pressed, the can beverage corresponding to the can beverage sample 106 is carried out to the product outlet 130. The return lever 132 is used to return the inserted coin from the return slot 134 or to return the change obtained by subtracting the can beverage purchase amount from the inserted coin or the inserted bill from the return slot 134. The slit 138 is for accelerating the heat radiation of the compressor 2 and the gas cooler 4 constituting a refrigerant cooling circuit disposed in an internal machine room (not shown).
[0042]
The refrigerant cooling circuit is the refrigerant cooling circuit of FIG. 1, and the products in the vending machine cabinet are effectively cooled by the fan 26 sending cool air around the evaporator 8 into the cabinet.
[0043]
The refrigerant cooling circuit of FIG. 1 can also be applied to vending machines other than can beverage vending machines. For example, the refrigerant cooling circuit in FIG. 1 may be applied to a vending machine for cup beverages to cool the water stored in the tank for the cooled beverage.
[0044]
=== Control operation of vending machine ===
Next, the control operation of the vending machine using the refrigerant cooling circuit of the present invention will be described with reference to FIG. FIG. 7 is a block diagram for explaining the control operation of the vending machine of the present invention.
[0045]
In FIG. 7, a main control unit 202 controls the vending machine, and includes a ROM, a CPU, a RAM, and peripheral circuits (I / O, timer, counter, etc.). More specifically, the ROM stores in advance program data for overall control of a plurality of sub-control units to be described later, and the CPU controls a plurality of sub-controls according to the result of decoding the program data read from the ROM. The RAM performs overall control of the units, and the RAM writes or reads out the calculation results by the CPU and various data from the plurality of sub-control units. On the hardware side, the ROM is a mask ROM that burns and fixes data in the manufacturing process, an EPROM that can repeatedly write and read data by erasing the data with ultraviolet light, or an EEPROM that can repeatedly write and read data by electrically erasing the data ( A nonvolatile memory such as a flash ROM). The CPU includes a program counter for designating an execution address of the ROM, an instruction decoder for decoding the contents read from the ROM, an arithmetic logic unit for performing a logical operation, an accumulator for temporarily storing operation data, and the like. The RAM is a volatile memory such as SRAM, and retains stored contents using a backup power source.
[0046]
The coin processing control unit 204, the banknote processing control unit 206, the customer service control unit 208, and the sales control unit 210 correspond to a plurality of sub control units, and in terms of hardware, the same ROM, CPU, and RAM as the main control unit 202 are provided. Built in.
[0047]
The coin insertion mechanism 212 includes a change change sensor for detecting change change, receives the input coin from the coin insertion slot 108, and returns change from the return slot 134 as necessary. The coin processing control unit 204 controls the coin insertion mechanism 212, and makes it possible to discriminate the denomination and correctness of inserted coins, calculate the number of denominations, store surplus coins in a safe, change payments, and the like. . Similar to the coin insertion mechanism 212, the bill insertion mechanism 214 includes a fishing bill out sensor for detecting the out of the bill, receives the inserted bill from the bill insertion slot 210, and inserts the bill into the bill as necessary. It may be returned from the mouth 110. The banknote processing control unit 206 controls the banknote insertion mechanism 214 to determine the inserted banknote denomination, correctness, etc., calculate the number of denominations, and pay out a bill. The coin processing control unit 204 and the banknote processing control unit 206 execute processing operations each time coin insertion and bill insertion are performed. Here, the coin processing control unit 204 and the coin insertion mechanism 212 constitute a coin identification device, and the bill processing control unit 206 and the bill insertion mechanism 214 constitute a bill identification device. In addition, the payment method of goods is not limited to said coin and banknote. For example, electronic payment may be performed using various cards or mobile terminals.
[0048]
The customer service surface 216 includes a display unit 112, a product selection button 116, a sale lamp 124, a sale stop lamp 126, and a change change lamp 128. The customer service control unit 208 controls the customer service surface 216. That is, the customer service control unit 208 turns on the sales lamp 124, the sales stop lamp 126, and the change-out lamp 128 according to the customer service instruction regarding the sale of canned beverages from the main control unit 202, the sales possible lamp 118 for each beverage sold, or The sold-out lamp 120 is turned on, and further, it is detected which of the plurality of product selection buttons 116 is pressed, and a detection signal at this time is transmitted to the main control unit 202.
[0049]
The sales mechanism 218 pays out the canned drink remaining at the bottom of the designated column and carries it out to the product outlet 130. The sales control unit 210 controls the sales mechanism 218 and carries out the can beverage desired by the user to the product outlet 130 in accordance with the sales instruction from the main control unit 202 in response to the detection signal from the customer service control unit 208. Is. The sales control unit 210 also controls the operation of the refrigerant cooling circuit 220 in FIG. 1 and corresponds to the control unit 18. The main control unit 202 and the sales control unit 210 may have the functions of the control unit 18 divided.
[0050]
The remote controller 114 is provided with a function key, numeric keys, and a display unit (organic EL, LCD, etc.) for displaying contents related to the operation of these keys on the front surface. The remote controller 114 is detachably disposed on the back surface of the front door 102, and is operated when performing column setting, price setting, maintenance, and the like for associating the product selection button 116 with a column. Transmit to the main control unit 202. Based on this operation information, the main control unit 202 instructs each of the coin processing control unit 204, the banknote processing control unit 206, the customer service control unit 208, and the sales control unit 210.
[0051]
The communication between the main control unit 202 and the sub control units 204, 206, 208, and 210 is a polling method in which the main control unit 202 has a preferential transmission right, or the main control unit 202 and the sub control unit 204. , 206, 208, 210 may be any of the contention systems having equal transmission rights.
[0052]
The refrigerant cooling circuit 220 of the present embodiment can be applied to vending machines installed in a wide range of locations regardless of whether indoors or outdoors, so that a normal refrigeration cycle can be continued for a long time, and the user can select a cooling product. It becomes possible to rapidly spread vending machines that can be purchased reliably.
The vending machine thus realized is a vending machine superior to the conventional one.
[0053]
=== Others ===
The above embodiment is for facilitating the understanding of the present invention, and does not limit the present invention. The present invention can be changed and improved without departing from the spirit of the present invention. Of course, the present invention includes equivalents.
[0054]
<Refrigerant>
In this embodiment, the refrigerant in the refrigerant cooling circuit is carbon dioxide, but the refrigerant in the refrigerant cooling circuit may be HFC other than carbon dioxide. That is, when the present invention is applied to a refrigerant cooling circuit of carbon dioxide, the high pressure side of the refrigerant cooling circuit can be prevented from becoming unnecessarily high, and when the present invention is applied to a refrigerant cooling circuit such as an HFC, The low pressure side of the refrigerant cooling circuit can be prevented from becoming unnecessarily low, and both the compressors 2 can perform normal compression operations, and the refrigerant cooling circuit can execute a stable refrigeration cycle.
[0055]
<Target for applying refrigerant cooling circuit>
In the present embodiment, the refrigerant cooling circuit 220 is applied to a vending machine, but is not limited to this. For example, the refrigerant cooling circuit 220 can be applied to commercial and household refrigerators, commercial freezer showcases, beverage supply dispensers installed in fast food stores, family restaurants, and the like.
[0056]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the refrigerant | coolant cooling circuit which can prevent the clogging of the refrigerator oil to a throttle part, and can perform the stable refrigerating cycle, and the vending machine using this refrigerant | coolant cooling circuit are realizable.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of a refrigerant cooling circuit of the present invention.
FIG. 2 is an example of a characteristic diagram showing a relationship between a control signal A (horizontal axis) and an amount of carbon dioxide passing through the electronic expansion valve 6 (vertical axis).
FIG. 3 is an example of a characteristic diagram showing a relationship between a carbon dioxide mixing ratio (horizontal axis) and pressure (vertical axis) of refrigerating machine oil.
FIG. 4 is an example of a characteristic diagram showing the relationship between the temperature (horizontal axis) and the viscosity (vertical axis) of refrigerating machine oil.
FIG. 5 is a flowchart for explaining the operation of the refrigerant cooling circuit of the present invention.
FIG. 6 is a diagram showing an example of the front surface of the vending machine according to the present invention.
FIG. 7 is a block diagram for explaining the control operation of the vending machine according to the present invention.
[Explanation of symbols]
2 Compressor
4 Gas cooler
6 Electronic expansion valve
8 Evaporator
12 Internal heat exchanger
14 Stepping motor
18 Control unit
20 timer
22 tables
24 memory
202 Main control unit
210 Sales Control Department
220 Refrigerant cooling circuit

Claims (6)

A compressor that compresses the refrigerant; a radiator that dissipates the refrigerant supplied from the compressor; a throttle that adjusts a flow rate of the refrigerant supplied from the radiator; and a refrigerant supplied from the throttle An evaporator for returning to the compressor, and a refrigerant cooling circuit having:
A throttle part control means for increasing the flow rate of the refrigerant in the throttle part for a predetermined time from the start of operation of the refrigerant cooling circuit,
The throttle control unit is capable of adjusting the refrigerant flow rate and the predetermined time in the throttle according to the power supply frequency of the compressor and the opening of the throttle.
A refrigerant cooling circuit characterized by that.   The refrigerant cooling circuit according to claim 1, wherein the radiator radiates the refrigerant supplied from the compressor in a supercritical pressure state.   The refrigerant cooling circuit according to claim 1, wherein the refrigerant is carbon dioxide.   4. The refrigerant cooling circuit according to claim 1, wherein the throttle portion is an electronic expansion valve whose valve opening is adjusted in accordance with an output of the throttle portion control means.   The refrigerant cooling circuit according to any one of claims 1 to 4, wherein the predetermined time is determined according to a viscosity of a refrigerating machine oil for the compressor. A compressor that compresses the refrigerant; a radiator that dissipates the refrigerant supplied from the compressor; a throttle that adjusts a flow rate of the refrigerant supplied from the radiator; and a refrigerant supplied from the throttle In an automatic vending machine comprising a refrigerant cooling circuit having an evaporator to be returned to the compressor,
The refrigerant cooling circuit includes a throttle control unit for increasing the flow rate of the refrigerant in the throttle for a predetermined time from the start of operation,
The throttle control unit is capable of adjusting the refrigerant flow rate and the predetermined time in the throttle according to the power supply frequency of the compressor and the opening of the throttle.
Vending machine characterized by that.

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