JP2002106983A - Cooling device and vending machine employing the cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device or a vending machine capable of facilitating safety countermeasure by reducing the amount of combustible refrigerant even when the combustible refrigerant is used as the refrigerant for a refrigerating cycle. SOLUTION: A compressor 8, a condenser 9, pressure reducing means 10-12 and evaporators 13-15 are connected in an annular circuit through a pipeline to constitute the refrigerating cycle by sealing mixture refrigerant containing the combustible refrigerant or a combustible refrigerant consisting of a single constituent into the annular circuit and the evaporators are arranged so as to be capable of cooling a predetermined amount while a reciprocating compressor is employed for the compressor and a motor-operated expansion valve, whose opening degree is made variable, is employed for the pressure reducing means. Accordingly, the amount of combustible refrigerant becomes smaller than a normal value and a cooling control in accordance with the cooling load can be effected, further, the amount of the combustible refrigerant can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration cycle cooling device using a flammable refrigerant and a vending machine using the device.

[0002]

2. Description of the Related Art In recent years, a refrigerant CFC used in a refrigeration cycle of a cooling device from the viewpoint of protecting the earth's ozone layer.
(Chlorofluorocarbon) -12 or HCFC
Use of a refrigerant containing a chlorine atom such as (hydrochlorofluorocarbon) -22 is regulated, and it is necessary to switch to a refrigerant having no ozone layer destruction ability. HFC (hydrofluorocarbon) is considered as a refrigerant having no ozone layer destruction ability, and as an alternative refrigerant for a refrigeration cycle in a vending machine using HCFC-22 refrigerant, R407C having a close boiling point is the first refrigerant. It is being adopted as a candidate.

[0003]

However, in the above-mentioned prior art, although the purpose of protecting the ozone layer can be achieved, from the viewpoint of preventing global warming, the efficiency of the refrigeration cycle as a refrigerant is high and the global warming is prevented. A refrigerant with a small coefficient is desired. Therefore, as a refrigerant having no ozone layer destruction ability and a small global warming potential, an HC (hydrocarbon) refrigerant can be considered. However, since HC-based refrigerants are flammable, care must be taken to prevent leakage of flammable refrigerants when using them as refrigerants in refrigeration cycles in cooling and heating devices, especially in vending machines. Thus, it is necessary to enhance the safety so that the flammable refrigerant leaked into the semi-enclosed space in the article storage is not ignited.

[0004] The present invention solves the conventional problems.
It is an object of the present invention to provide a cooling device that can safely perform cooling even when a combustible refrigerant is used as a refrigerant of a refrigeration cycle, and a vending machine using the device.

[0005]

According to a first aspect of the present invention, a compressor, a condenser, a pressure reducing means, and an evaporator are connected to an annular circuit by piping, and a mixed refrigerant containing a combustible refrigerant or a single refrigerant is connected. A refrigeration cycle in which a flammable refrigerant composed of one component is sealed in the annular circuit is arranged, the evaporator is arranged so as to be able to cool a predetermined position, the compressor is a reciprocating compressor, and the pressure reducing means is Each of the electric expansion valves has a variable opening degree.

According to the above means, the use of the reciprocating compressor lowers the pressure in the shell of the compressor, reduces the amount of the refrigerant dissolved into the refrigerating machine oil in the compressor, and reduces the refrigerant gas density at the lower pressure. Since it is small, the amount of the flammable refrigerant sealed in the annular circuit can be made smaller than usual. The use of the electric expansion valve enables the control of the flow rate of the refrigerant according to the cooling load, and has the effect of reducing the maximum required refrigerant amount and further reducing the required amount of the flammable refrigerant. Further, even if the predetermined position arranged so that the evaporator can be cooled is, for example, a storage of a vending machine, even if flammable refrigerant leaks into the storage by mistake from the evaporator, the amount is reduced. Has a function that can be.

According to a second aspect of the present invention, in the first aspect, the reciprocating compressor is of a displacement control type.

According to the above means, the use of the capacity control type reciprocating compressor makes it possible to control the cooling in accordance with the cooling load, and the use of the reciprocating compressor and the electric expansion valve allows the flammable refrigerant in the annular circuit of the refrigeration cycle to be cooled. It has the effect of reducing the required amount.

According to a third aspect of the present invention, in the first or second aspect, the condenser has a tube in which the combustible refrigerant flows, which is thinner than a tube of the evaporator.

[0010] According to the above means, the tube constituting the condenser becomes thinner, and has the effect of reducing the accumulation of the flammable refrigerant in the condenser. Further, for example, when the condenser is constituted by the fin-type heat exchanger, the space between the meandering pipes can be made wider than that of a normal pipe, thereby reducing dust clogging due to gas flowing between the pipes. It has the effect of doing.

According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, a blower for circulating air to the evaporator and the condenser is provided, and the blower has a variable speed. Things.

According to the above means, it is possible to change the speed of the blower according to the cooling load.
In addition to the above operation, the rotation of the blower can be controlled according to the cooling load, and the required amount of combustible refrigerant in the annular circuit of the refrigeration cycle can be reduced.

According to a fifth aspect of the present invention, a compressor, a condenser, and a plurality of evaporators each having an electric expansion valve are connected to an annular circuit by piping, and a mixed refrigerant containing a combustible refrigerant or a single component is used. A refrigeration cycle in which a flammable refrigerant is sealed in the annular circuit, and the evaporator is arranged so that a predetermined position can be cooled, and the evaporator operable by calculating from the amount of the charged refrigerant and a cooling load. And a control means for selecting and operating the operation.

According to the above means, the control means makes it possible to select an operable evaporator that can respond to the cooling load on the basis of the amount of the charged refrigerant. It has a cooling effect by efficient operation.

According to a sixth aspect of the present invention, in the fifth aspect, the operation is set to a maximum of two evaporators.

According to the above means, it is possible for the control means to select up to two operable evaporators corresponding to the cooling load on the basis of the amount of the charged refrigerant. Also has an efficient cooling action that does not cause a shortage of refrigerant.

According to a seventh aspect of the present invention, a compressor, a condenser, a pressure reducing means, and an auxiliary heat exchanger are connected to an annular circuit by piping, and a mixed refrigerant containing a combustible refrigerant or a single component combustible refrigerant. Is constituted in a unit of a refrigeration cycle sealed in the annular circuit, and the refrigeration cycle is arranged by a heat exchanger arranged so that a secondary refrigerant that has exchanged heat with the auxiliary heat exchanger can be circulated to cool a predetermined position. It is of a secondary refrigerant type, and the refrigeration cycle unit is provided at a position communicating with the outside air.

According to the above means, the flammable refrigerant circulates only in the unit of the refrigeration cycle, and the flammable refrigerant is not used in the secondary refrigerant circuit. Has the effect of reducing the amount of Further, there is no possibility that the flammable refrigerant leaks into the storage from the heat exchanger, and thus, for example, it works so as not to cause ignition by a heating heater, a fan in the storage, or the like. Further, even if the flammable refrigerant leaks from the unit of the refrigeration cycle by mistake, since the unit is at the position communicating with the outside air, the unit has a function of being diffused by the action of the gas leading to the outside air.

The invention according to claim 8 is a vending machine provided with the cooling device according to any one of claims 1 to 7, so that the refrigeration is performed by the operation according to claims 1 to 7. It has the effect of reducing the amount of flammable refrigerant sealed in the annular circuit of the cycle and enabling safe and efficient cooling operation.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A cooling and heating apparatus according to the present invention and a vending machine using the cooling and heating apparatus will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 shows a first embodiment of the present invention.
FIG. 2 is an external view showing a cooling and heating system of a vending machine, which is a cooling and heating device according to an embodiment corresponding to the invention described in claims 2, 3, 4, and 8; It is a control block diagram of the vending machine.

Reference numeral 1 denotes a main body of a vending machine as a cooling and heating device, which has a middle room and left and right storages 2, 3, 4 at an upper portion and a machine room 5 at a lower portion. Each of the storages 2, 3, and 4 is a heat insulating structure including an inner wall 6a forming an outer shell and a partition wall, an outer wall 6, and a foamed heat insulator 7 having closed cells therebetween. The main body 1 of the vending machine connects the cooling and heating system to the annular circuit through a pipe connecting the compressor 8, the condenser 9, the electric expansion valves 10, 11, 12, and the evaporators 13, 14, 15 as pressure reducing means. The refrigerant circuit includes a refrigeration cycle in which a mixed refrigerant containing a flammable refrigerant or a flammable refrigerant composed of a single component is sealed in the annular circuit, and heating heaters 16, 17, and 18.

That is, the evaporators 13, 14, 15 and the heaters 16, 17, 18 are paired with the storages 2, 3,.
4 are arranged so as to be able to cool and heat a storage as a predetermined position, and the ring circuit of the refrigeration cycle of each storage is the same, so the explanation will be given using the example of the storage 2. I do. The compressed refrigerant discharged from the compressor 8 flows as indicated by an arrow, flows into the condenser 9 and is condensed, and is condensed.
The pressure is reduced to 0, and flows into the evaporator 13, evaporates, and flows as indicated by an arrow to be drawn into the compressor 8 to form a circulation circuit of a cooling action.

The compressor 8 uses a reciprocating compressor that can reduce the amount of refrigerant in the shell because the pressure inside the shell is low and the refrigerant can be less dissolved into the refrigerating machine oil, and the low pressure reduces the density of the refrigerant gas. When the capacity of the refrigeration cycle is controlled by the frequency control and efficient control is possible according to the cooling load, and the amount of flammable refrigerant sealed in the annular circuit of the refrigeration cycle is changed by using another type of compressor. It is configured to be less than that.

The condenser 9 has an inner diameter corresponding to that of the evaporator 1.
It is configured to be thinner than the pipe inner diameter of 3 to 15 to reduce the flammable refrigerant stagnation in the condenser 9 and reduce the pressure loss,
The amount of the flammable refrigerant sealed in the annular circuit of the refrigeration cycle described above is reduced as much as possible. The electric expansion valves 10 to 1 used as pressure reducing means are also used.
2, the degree of opening can be adjusted according to the cooling load, and the flow rate of the refrigerant can be controlled, and the maximum required refrigerant amount can be reduced to enable efficient cooling operation, which is enclosed in the annular circuit of the refrigeration cycle. The amount of the flammable refrigerant can be further reduced.

The compressor 8, the condenser 9, the electric expansion valves 10-1 constituting the refrigeration cycle of the cooling system described above.
2, and a large number of welds 19 with each pipe including the evaporators 13 to 15, the compressor 8, and the condenser 9 are arranged in the machine room 5 which always communicates with the outside air through the vents 20, 21.

Reference numerals 22, 23, and 24 denote internal fans provided at the bottoms of the storages 2 to 4, respectively. Heat exchanged cold air and heating heaters 16-18
The warm air exchanged with the above is forcibly circulated through the storages 2 to 4. Numeral 25 denotes an external fan provided in the machine room 5, which prevents the flammable refrigerant leaking by using a molded motor from being ignited, and through the vents 20 and 21, the compressor 8 and the condenser 9
Dissipates heat.

Inside fan 22 to 24 and outside fan 2
No. 5 allows the speed to be adjusted according to the cooling load, and enables an efficient cooling operation according to the magnitude of the cooling load even in a refrigeration cycle of a small amount of the flammable refrigerant sealed in the annular circuit. Like that.

As shown in FIG. 2, reference numeral 26 denotes a main control unit for controlling the vending machine, and reference numeral 27 denotes a cooling unit for setting each of the storages 2 to 4 to a cooling storage or a heating storage via the main control unit 26. A temperature setting unit 28 includes a capacity of the compressor 8, a degree of opening of the electric expansion valves 10 to 12, and a heating heater 1 based on a temperature detected by an internal temperature sensor 29 as a cooling load detecting unit provided in the storage.
6 to 18, a cooling and heating control unit for controlling the on-off of the internal fans 22 to 24 and the external fan 25, which is constituted by a microcomputer or the like.

Reference numeral 30 denotes an abnormal temperature sensor provided in the storages 2 to 4. When the heating heaters 16 to 18 abnormally rise in temperature due to a failure, the temperature is detected and transmitted to the cooling and heating control unit 28. Then, the power supply to the failed heating heaters 16 to 18 is stopped by the cooling and heating control unit 28. In the drawing, 31 is a front door made of a heat insulating structure of the vending machine main body 1, 32 is a product stacked on a sales shelf of each storage 2 to 4, and 33 is a front door 3
A product selection button 34 provided in the table 1 is a keyboard provided on the back side of the front door 31 for inputting various data. The electric expansion valves 10 to 12 have a pressure reducing function and an opening / closing function.

In the above embodiment, cooling and heating of the storages 2 to 4 in the vending machine will be described. That is, when all of the storages 2 to 4 are used as the cooling storage, the cooling and heating setting unit 27 sets the cooling to all. When the cooling and heating control unit 28 operates the in-compartment fans 22 to 24, the out-of-compartment fan 25, and the compressor 8, the compressed refrigerant is condensed in the condenser 9, and then is conveyed to the electric expansion valves 10 to 12. The pressure is reduced by branching. Subsequently, the depressurized refrigerant evaporates in each of the evaporators 13 to 15, merges with each other, and returns to the compressor 8. Storage 2-4 cooled by each evaporator 13-15
Is forcibly circulated by the internal fans 22 to 24.

In particular, in the present invention, since a reciprocating compressor is used for the compressor 8, the amount of flammable refrigerant sealed in the annular circuit of the refrigeration cycle can be reduced.
Generally, the refrigerant dissolves in the refrigerating machine oil contained in the compressor.The higher the pressure and the higher the temperature, the greater the amount of the dissolution, which decreases the cooling effect of the refrigeration cycle. Is filled with a large amount of refrigerant.

However, when flammable refrigerant is sealed in the annular circuit of the refrigeration cycle, the amount of refrigerant cannot be simply increased in the case of accidental leakage. Therefore, in the present invention, the refrigerating compressor having a low pressure in the shell is used to reduce the amount of the flammable refrigerant remaining in the refrigerating machine oil (dissolved amount), and the low pressure has a lower density of the refrigerant gas. The amount of refrigerant used was reduced. Accordingly, in the storages 2 to 4 of the vending machine as the predetermined positions where the evaporators 13 to 15 and the heating heaters 16 to 18 are arranged so as to be able to cool and heat, the flammable refrigerant leaks by mistake. Even in such a case, measures to prevent ignition of the leaked flammable refrigerant can be relatively easily performed, and global warming can be prevented.

Further, according to the present invention, the electric expansion valves 10 to 1 whose opening degree can be adjusted as pressure reducing means for the freezing cycle can be adjusted.
2 allows the refrigerant flow rate to be controlled in accordance with the cooling load, thereby reducing the maximum required refrigerant amount, enabling efficient cooling operation, and reducing the amount of flammable refrigerant enclosed in the annular circuit of the refrigeration cycle. The required amount can be further reduced. That is, the required capacity of the refrigeration cycle changes according to the load of the cans, which are the products in the storage, and the outside air temperature, and the required refrigerant amount and the appropriate decompression amount also change. And when the decompression means is fixed in decompression amount like a capillary tube,
It is designed to handle large loads including the compressor.

However, in the present invention, the electric expansion valves 10 to 12 whose opening degree can be adjusted are used, and the actual temperature signal of each storage detected by the internal temperature sensor 29 controls the cooling and heating control unit 28. Via the main controller 26, a signal calculated based on the reference set temperature of the load stored in the main controller 26 in advance, and the degree of superheat of the evaporators 13 to 15 (refrigerant state at the outlet of the evaporator). ) Is received from the cooling and heating control unit 28, and the degree of opening of each of the electric expansion valves 10 to 12 is adjusted to an optimal throttle according to the load. Therefore, since the optimal throttle according to the load is possible in this way, and a certain level of capacity control can be performed, the amount of combustible refrigerant can be reduced by controlling the required amount of refrigerant, and the compressor can be downsized. In addition, the amount of refrigerant in the shell is reduced due to the downsizing of the compressor, and the piping in the refrigeration cycle can be made narrower, so that the amount of flammable refrigerant can be reduced.

In the present invention, since the reciprocating compressor used in the refrigeration cycle is of a capacity control type (inverter compressor), the actual temperature of each storage detected by the internal temperature sensor 29 is the same as described above. The temperature signal is taken into the main control unit 26 via the cooling / warming control unit 28, and a signal calculated based on the temperature signal and the reference set temperature of the load stored in the main control unit 26 in advance and the evaporators 13 to 15
The cooling and heating control unit 28 can control the frequency of the capacity of the compressor 8 according to the load in accordance with the signal of the magnitude of the cooling load calculated from the signal obtained by detecting the degree of superheat of the compressor (the refrigerant state at the outlet of the evaporator). . Therefore, the capacity of the compressor 8 can be controlled in accordance with the load in this way, and the control of the required refrigerant amount can reduce the total flammable refrigerant amount.

In the present invention, since the condenser 9 has a tube diameter smaller than that of the evaporators 13 to 15, the flammable refrigerant sealed in the annular circuit of the refrigeration cycle can be further reduced. But you can do less. That is, the condenser generally has a large amount of refrigerant, but the condenser 9 uses a narrower tube than the evaporator, so that the flammable refrigerant stays in the condenser 9 and the pressure loss decreases. Thus, the total amount of combustible refrigerant can be reduced. Then, for example, when the condenser 9 is configured by a fin-type heat exchanger, the space between the meandering thin tubes can be made wider than that of the ordinary tube, and dust clogging due to gas flowing therebetween can be prevented. It can also be reduced.

In the present invention, the speed of the internal fans 22 to 24 and the external fan 25 is adjustable, so that an efficient cooling operation can be performed according to the cooling load. That is, in the same manner as described above, the actual temperature signal of each storage detected by the internal temperature sensor 29 is taken into the main control unit 26 via the cooling and heating control unit 28, and the main control unit 26 Of the cooling load calculated from the signal calculated based on the reference set temperature of the load and the signal obtained by detecting the degree of superheat (pressure) of the evaporators 13 to 15 (refrigerant state at the outlet of the evaporator). In accordance with the signal, the cooling and heating control unit 28 can control the rotation speeds of the internal fans 22 to 24 and the external fan 25 according to the load. Therefore,
In this way, the rotation speeds of the internal fans 22 to 24 and the external fan 25 can be controlled according to the load, and an efficient cooling operation can be performed with a small amount of refrigerant.

As described above, in the present invention, a reciprocating compressor is used as a compressor, and an electric expansion valve having a variable opening degree is used as a pressure reducing means. Because the amount of refrigerant remaining in the machine oil can be reduced and the density of the refrigerant gas is lower at low pressure, the required amount of the entire flammable refrigerant can be reduced, and the refrigerant flow rate can be controlled by controlling the degree of opening of the electric expansion valve. This makes it possible to reduce the maximum required refrigerant amount and easily respond to the maximum cooling load.Since the compressor can be reduced in size, it is possible to reduce the amount of refrigerating machine oil and the evaporator and the condenser, making it possible to reduce the amount of flammable refrigerant. The amount of sealing can be reduced.

In the above embodiment, the evaporator 13
The welded portions connected to the annular circuit constituting the refrigeration cycle of Nos. 1 to 15, and all other welded portions 19 are vent holes 20, 21.
The evaporators 13 to 15 and the heating heater 16
In the storages 2 to 4 of the vending machine, which are arranged at predetermined positions so that cooling and heating can be performed, there is no portion where the flammable refrigerant is likely to leak into the storage. As a result, the flammable refrigerant is not ignited, and safety can be improved. Even if the flammable refrigerant leaks from the weld 19 by mistake, it can be prevented from igniting due to a heat source or the like due to circulation by the outside fan 25 or diffusion by the outside air flowing by natural convection. When the flammable refrigerant leaks into the machine room 5, it is detected by a gas sensor, and the cooling and heating control unit 28 forcibly operates the external fan 25 to discharge the flammable refrigerant to the outside of the machine room 5 according to the detection signal. In addition, when the above-described flammable refrigerant including the above-mentioned flammable refrigerant leaks, it may be displayed on the front door 31.

(Embodiment 2) FIG. 3 shows a fifth embodiment of the present invention.
And FIG. 6 is a control block diagram of a cooling and heating system of a vending machine as a cooling and heating device according to an embodiment corresponding to the invention described in claims 6 and 8. FIG. I will explain using it.

The invention of this embodiment is characterized in that the first embodiment is provided with a control means for selecting and operating an operable evaporator based on the amount of refrigerant charged and the cooling load in the annular circuit of the refrigeration cycle. Only differs from the invention of
Portions having the same configuration and operation and effect will be denoted by the same reference numerals, detailed description thereof will be omitted, and different portions will be mainly described.

The main control section 26a and the cooling / heating control section 28 as control means store data in a storage section in advance in the form of a matrix of a load magnitude and a necessary refrigerant amount of a refrigeration cycle corresponding thereto. As described in the first embodiment, the actual temperature signal of each storage detected by the internal temperature sensor 29 is taken into the main control unit 26a via the cooling and heating control unit 28, and the main control unit 26a The signal calculated based on the reference set temperature of the load stored in 26a and each evaporator 1
According to the signal of the magnitude of the cooling load of each storage calculated from the signal of detecting the degree of superheat (refrigerant state at the outlet of the evaporator) of 3 to 15, from the above data, the small amount of refrigerant sealed in the cooling system is selected. An operable evaporator 1 that can handle
Select a maximum of two from 3 to 15, and select the cooling and heating control unit 2
8 is operated.

In the above embodiment, the operations of cooling and heating the storages 2 to 4 in the vending machine are the same as those described in the first embodiment.

During the cooling operation, for example, as a result of the replenishment of the products 32 in the storage 2 and the replenishment, the temperature in the storage 2 rises and the main control is performed based on the signal detected by the temperature sensor 29 in the storage. The cooling load calculated by the unit 26a increases. The cooling operation of all the storages 2 to 4 has been performed so far. However, due to the large cooling load of the storage 2, the simultaneous operation of the three storages cannot be performed. The main control unit 26a determines that only the storage 2 is operable based on the data, and operates the compressor 8 by the cooling and heating control unit 28 to control the refrigeration cycle circuit corresponding to the storage 2. During this time, the circulation of the refrigerant is stopped in the refrigeration cycle circuits corresponding to the storages 3 and 4, and the staying refrigerant is recovered and circulated all through the refrigeration cycle circuit corresponding to the storage 2.

By this cooling operation, the cooling load of the storage 2 is reduced, and the combined load of this cooling load and the cooling loads of the other storages 3 and 4 allows the cooling operation of all the storages 2 to 4 to be performed. When the load is reached, all of the storages 2 to 4 are again cooled. When such an operable evaporator is selected and controlled, electric open / close valves are respectively connected to the inlet and the outlet of the evaporator in the refrigeration cycle circuit of the non-operating storage to control the opening / closing by cooling and heating. Control unit 2
8 is performed.

As described above, in the present invention, up to two operable evaporators capable of responding to the cooling load based on the amount of the charged refrigerant are selected by the main control unit 26a as the control means and the cooling / heating control unit 28. It is possible to perform an efficient cooling operation that does not cause a shortage of the refrigerant even if a small amount of the flammable refrigerant is used. In particular, in a cooling system that encloses flammable refrigerant in the annular circuit of the refrigeration cycle, it is relatively easy to take measures to reduce the amount of flammable refrigerant and prevent ignition of flammable refrigerant in the event of accidental leakage of refrigerant. And prevent global warming.

(Embodiment 3) FIG. 4 shows a seventh embodiment of the present invention.
FIG. 9 is an external view showing a cooling and heating system of a vending machine, which is a cooling and heating device according to an embodiment corresponding to the invention described in claim 8. The invention of this embodiment differs from the invention of the first embodiment only in that the refrigeration cycle is set to the secondary refrigerant system and the flammable refrigerant is not circulated to the heat exchanger provided through the storage. Portions having the same configuration and operation and effect will be denoted by the same reference numerals, detailed description thereof will be omitted, and different portions will be mainly described.

The unit of the refrigeration cycle includes a compressor 8, a condenser 9, an electric expansion valve 35, and an indirect auxiliary heat exchanger 36 connected to an annular circuit by piping, and a mixed refrigerant containing a combustible refrigerant or a single component. Is sealed in the annular circuit. 13a, 14a, 15a are each storage 2,
A heat exchanger that cools the inside of the refrigerator by passing through each of the electric flow control valves 10a, 11a, 12a, and a common circulation pump 3.
7. Connected to the auxiliary heat exchanger 36 by piping to form annular secondary refrigerant circuits respectively corresponding to the heat exchangers 13a, 14a, and 15a, and enclose a refrigerant of antifreeze. Further, the heating heaters 16, 17, and 18 are configured so as not to limit the heat generation capacity without taking into consideration the prevention of ignition of the combustible refrigerant. The amount of the flammable refrigerant sealed in the pipe circuit of the present refrigeration cycle is directly determined by the heat exchanger 13.
The amount circulating through the secondary refrigerant circuit of a to 15a is reduced by an amount not required.

In the above-described embodiment, when the storages 2 to 4 are used as the cooling storages, the cooling and heating setting unit 27 sets all cooling, and the cooling and heating control unit 28 operates the compressor 8 and the circulation pump 37. I do. Then, the compressed refrigerant discharged from the compressor 8 is condensed in the condenser 9, decompressed by the electric expansion valve 35, and then evaporated in the auxiliary heat exchanger 36 to return to the compressor 8. On the other hand, each heat exchanger 13a-15 in the secondary refrigerant circuit
A refrigerant is circulated in a by a circulation pump 37, and the circulating refrigerant is cooled by the heat of evaporation in the auxiliary heat exchanger 34, and radiates heat in each of the heat exchangers 13a to 15a to cool the inside of the refrigerator.

When the storages 2 to 4 are used as heating chambers, the cooling and heating setting section 27 sets all heating, and the cooling and heating control section 28 controls each of the heating heaters 16, 17 and 18. Apply electricity to warm the interior.

In particular, in the present invention, the heat exchangers 13a to 15a
The heat exchangers 13a to 15a are located in the secondary refrigerant circuit of the refrigeration cycle in the storages 2 to 4 of the vending machine, which are predetermined places where the heaters 16 to 18 are arranged so that they can be cooled and heated. Since the refrigerant of the antifreeze liquid is sealed, even if the refrigerant accidentally leaks into the storage from the heat exchangers 13a to 15a, the problem such as the flammable refrigerant does not occur. Also, since it is not necessary to consider suppressing ignition of the flammable refrigerant,
It is possible to design only in consideration of heating, and it is possible to efficiently heat the storage and prevent global warming.

The unit of the refrigeration cycle is located in the machine room 5 which communicates with the outside air through the vents 20 and 21, and the amount of the flammable refrigerant is directly controlled by the heat exchangers 13a to 15a.
Because it is the secondary refrigerant system of the refrigeration cycle that does not need to consider the amount circulated in the pipe circuit, even if the flammable refrigerant leaks, it is diffused by the action of the gas flowing to the outside air because the amount is small even if it leaks. Measures can be easily prevented.

In this embodiment, the heat exchangers 13a to 13a
Although the case where the storage is cooled using the 15a has been described, the refrigerating cycle can be switched to the heat pump type to heat the storage.

[0055]

As described above, according to the first aspect of the present invention, a compressor, a condenser, a decompression means, and an evaporator are connected to an annular circuit by piping, and a mixed refrigerant containing a combustible refrigerant or a single component. A refrigeration cycle in which a flammable refrigerant is sealed in the annular circuit, the evaporator is arranged so as to be able to cool a predetermined position, the compressor is a reciprocating compressor, and the decompression means is an opening degree. It is made by using each electric expansion valve with variable, and the inside of the compressor becomes low pressure,
In addition, the degree of opening of the electric expansion valve can be controlled, and the amount of flammable refrigerant sealed in the circuit of the refrigeration cycle can be reduced.
In addition, the predetermined position where the evaporator can be cooled is, for example, a storage of a vending machine, and even if a flammable refrigerant leaks from the evaporator by mistake, the amount of the flammable refrigerant is small. Measures can be made easier.

According to a second aspect of the present invention, in the first aspect, the reciprocating compressor is of a capacity control type, and can perform cooling control according to a cooling load, and is enclosed in a circuit of a refrigeration cycle. The amount of the flammable refrigerant can be further reduced.

According to a third aspect of the present invention, in the first or second aspect, the condenser is formed by making a pipe through which a combustible refrigerant flows thinner than an evaporator pipe. And the pressure loss of the flammable refrigerant is reduced, and the amount of the flammable refrigerant in the refrigeration cycle can be reduced. Further, for example, when the condenser is constituted by the fin-type heat exchanger, the space between the meandering pipes becomes wider than that of a normal pipe, so that dust clogging caused by gas flowing between the pipes can be reduced.

According to a fourth aspect of the present invention, in any one of the first to third aspects, a blower for circulating air to the evaporator and the condenser is provided, and the blower is set to a variable speed. Therefore, it becomes possible to change the speed of the blower in accordance with the cooling load, and it is possible to further reduce the amount of flammable refrigerant charged into the annular circuit of the refrigeration cycle.

According to a fifth aspect of the present invention, a compressor, a condenser, a plurality of evaporators each having an electric expansion valve are connected to an annular circuit by piping, and a mixed refrigerant containing a combustible refrigerant or a single component is connected. A refrigeration cycle in which a flammable refrigerant is sealed in the annular circuit, and the evaporator is arranged so that a predetermined position can be cooled, and the evaporator operable by calculating from the amount of the charged refrigerant and a cooling load. In the cooling operation, it is possible to always select the operable evaporator corresponding to the cooling load based on the amount of the enclosed refrigerant, and the small amount enclosed in the refrigeration cycle can be selected. Even if the flammable refrigerant is used, an efficient cooling operation without running out of the refrigerant can be performed.

According to a sixth aspect of the present invention, in the fifth aspect, the operation is set to a maximum of two evaporators, and it is possible to select a maximum of two operable evaporators. Thus, even with a small amount of flammable refrigerant, an efficient cooling operation can be performed without running out of refrigerant.

According to a seventh aspect of the present invention, a compressor, a condenser, a pressure reducing means, and an auxiliary heat exchanger are connected to an annular circuit by piping, and a mixed refrigerant containing a combustible refrigerant or a single component combustible refrigerant. Is constituted in a unit of a refrigeration cycle sealed in the annular circuit, and the refrigeration cycle is arranged by a heat exchanger arranged so that a secondary refrigerant that has exchanged heat with the auxiliary heat exchanger can be circulated to cool a predetermined position. It is a secondary refrigerant system, and the refrigeration cycle unit is provided at a position communicating with the outside air. The amount of flammable refrigerant can be reduced by the amount of circulation of the secondary refrigerant circuit having a heat exchanger, and global warming can be reduced. Prevention can be achieved. Also, even if the flammable refrigerant leaks from the refrigeration cycle unit accidentally,
The gas is diffused by the action of the gas leading to the outside air, so that measures for preventing ignition can be easily performed.

The invention according to claim 8 is a vending machine provided with the cooling device according to any one of claims 1 to 7, so that the effects of the invention according to claims 1 to 7 can be obtained. Thus, it is possible to provide a vending machine capable of performing efficient cooling operation while preventing global warming by using a flammable refrigerant.

[Brief description of the drawings]

FIG. 1 is an external view showing a cooling and heating system of a vending machine according to a first embodiment of a cooling device of the present invention.

FIG. 2 is a control block diagram of a vending machine as the cooling device.

FIG. 3 is a control block diagram of a vending machine according to a second embodiment of the cooling device of the present invention.

FIG. 4 is an external view showing a cooling and heating system of a vending machine according to a third embodiment of the present invention;

[Explanation of symbols]

 2, 3, 4 Storage (predetermined position) 5 Machine room (position communicating with the outside air) 8 Compressor 9 Evaporator 13, 14, 15 Evaporator 13a, 14a, 15a Heat exchanger 19 Welded part 20, 21 Vent holes 26, 26a Main control unit (control means) 28 Cooling / heating control unit (control means) 36 Auxiliary heat exchanger 37 Circulation pump

Claims (8)

[Claims] 1. A compressor, a condenser, a pressure reducing means, and an evaporator are connected to an annular circuit by piping, and a mixed refrigerant containing a flammable refrigerant or a flammable refrigerant composed of a single component is sealed in the annular circuit. A refrigeration cycle is configured, the evaporator is arranged so as to be able to cool a predetermined place, the compressor is provided with a reciprocating compressor, and the pressure reducing means is provided with an electric expansion valve having a variable opening degree. apparatus. 2. The cooling device according to claim 1, wherein the reciprocating compressor is of a capacity control type. 3. The cooling device according to claim 1, wherein the condenser has a tube in which the combustible refrigerant flows, which is made thinner than a tube of the evaporator. 4. The cooling device according to claim 1, further comprising a blower for circulating air to the evaporator and the condenser, wherein the blower has a variable speed. 5. A compressor, a condenser, and a plurality of evaporators each having an electric expansion valve are connected to an annular circuit by piping, and a mixed refrigerant containing a flammable refrigerant or a single component flammable refrigerant is supplied to the annular circuit. Control means for configuring a refrigeration cycle enclosed in a circuit, arranging the evaporator so that a predetermined position can be cooled, selecting the operable evaporator based on the amount of the enclosed refrigerant and a cooling load, and operating the selected evaporator. A cooling device provided with. 6. The cooling device according to claim 5, wherein the operation is set to a maximum of two evaporators. 7. A compressor, a condenser, a pressure reducing means, and an auxiliary heat exchanger are connected to an annular circuit by piping, and a mixed refrigerant containing a flammable refrigerant or a flammable refrigerant composed of a single component is sealed in the annular circuit. The refrigeration cycle is configured as a unit of a refrigeration cycle, and the refrigeration cycle is changed to a secondary refrigerant system by a heat exchanger arranged to circulate a secondary refrigerant having exchanged heat with the auxiliary heat exchanger and cool a predetermined position. A cooling device in which a refrigeration cycle unit is provided at a position communicating with outside air. 8. A vending machine provided with the cooling device according to claim 1. Description: