JP2009127893A - Refrigerant circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive refrigerant circuit of high reliability. <P>SOLUTION: A first refrigerant valve 8 is closed, and a second refrigerant valve 21 is opened when a signal output by an ice bank sensor 93 indicates the amount of an ice bank B larger than a prescribed amount, and a signal outputted by an ice storage amount sensor 94 of an auger-type ice making machine 20 indicates the amount of ice storage smaller than the prescribed amount, a liquid refrigerant of low temperature and low pressure passing through the second refrigerant valve 21 is evaporated by an evaporator 25 for the ice making machine, drinking water ices on an ice-making cylinder inner wall surface by the evaporative latent heat, and thin ice on the ice-making cylinder inner wall surface is pushed up while being scraped off by rotating an auger, and compressed by an extruding head to make ice. A control portion 90 closes the second refrigerant valve 21 after the lapse of a prescribed time from the stop of operations of a compressor 2 and a blower 5, when the ice bank sensor 93 and the ice storage amount sensor 94 output signals of amounts larger than prescribed amounts with respect to both the amount of the ice bank B and the amount of the ice storage. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention provides a cooling water tank for cooling syrup and dilution water and an auger type ice making machine for producing ice by cooling drinking water to prepare and sell cup beverages and cool can beverages for sale. The present invention relates to a refrigerant circuit provided in a can vending machine.

There is known a cup-type vending machine that sells a cold beverage prepared by adding ice to a mixture of syrup and diluted water. In such a cup-type vending machine, when money is inserted and the cold beverage selection button is pressed, the syrup and dilution water cooled in the cooling water tank are injected and mixed into the cup supplied from the cup supply device, In addition, cold beverages that have been adjusted by placing ice that has been made and stored in an auger type ice maker are sold to users from the sales outlet. In this way, in order to sell and sell cold beverages in cup-type vending machines, a cooling water tank that cools syrup and dilution water, an auger type ice maker that cools drinking water and produces ice, a cooling water tank, A refrigerant circuit for cooling the auger type ice making machine is provided.
In the cooling water tank, side surfaces and a bottom surface are constituted by heat insulating walls, and cooling water for cooling syrup and dilution water is stored in a substantially rectangular parallelepiped water tank opened upward. Then, the evaporation pipe of the refrigerant circuit (hereinafter referred to as “cooling water evaporator”) in which the metal pipe is wound in a coil shape is immersed in cooling water, and the latent heat of vaporization (heat of vaporization) generated when the liquid refrigerant is evaporated. An ice bank (ice soul) is formed in the peripheral area of the cooling water evaporator, and the temperature of the cooling water is maintained at approximately 0 ° C. by using the heat storage of the ice bank. Furthermore, in the vicinity of the cooling water evaporator immersed in the cooling water, a plurality of cooling pipes in which stainless steel pipes are coiled are made to correspond to the number of syrups and dilution water that are the ingredients of cold beverages sold. Soaked in cooling water.

In addition, an auger type ice maker that produces ice to be used when preparing cold beverages is an ice making unit that cools drinking water supplied from a drinking water tank to make ice, and an ice storage unit that stores the produced ice on a cocoon child. It consists of and.
The ice making unit includes a drive motor, an auger (screw-like rotary cutting blade) connected via a speed reducer that reduces and transmits the rotation of the drive motor, an ice making cylinder through which the auger is inserted, an ice making cylinder Encloses the refrigerant circuit evaporation pipe (hereinafter referred to as “ice-maker evaporator”) wound around the outer peripheral surface, the ice compression extrusion head provided above the auger, the ice-making cylinder and the ice-maker evaporator The drinking water supplied from the drinking water tank by the latent heat of evaporation of the refrigerant flowing through the ice making machine evaporator wound around the outer surface of the ice making cylinder, The ice on the inner wall surface of the ice making cylinder is pushed up while being scraped by rotating an auger and compressed by an extrusion head to produce ice.
The ice storage section has an ice storage chamber composed of a heat insulating wall with a circular cross section at the top of the ice making section. Inside the ice storage section is an agitator for stirring ice pieces attached to a rotating shaft coaxial with the auger, an agitator and ice storage It is equipped with an ice-loading cocoon (having the role of draining the melted water in which the ice melts) disposed between the bottom of the chamber.

The refrigerant circuit compresses a low-temperature and low-pressure gas refrigerant as a working medium into a high-temperature and high-pressure gas refrigerant, and cools the high-temperature and high-pressure gas refrigerant compressed by the compressor with air sent from a blower. For a low temperature and high pressure liquid refrigerant, an evaporator for cooling water immersed in the cooling water of the cooling water tank, and an ice making machine wound around the outer surface of an auger type ice making machine An evaporator, a first refrigerant valve that squeezes and expands a low-temperature and high-pressure liquid refrigerant with a capillary tube and supplies the refrigerant as a low-temperature and low-pressure liquid refrigerant to the evaporator for cooling water, and a low-temperature and high-pressure liquid refrigerant with an expansion valve Liquid refrigerant supplied to the evaporator for cooling water and the evaporator for ice making machine, which is composed of a second refrigerant valve that supplies low temperature and low pressure liquid refrigerant to the ice machine evaporator and a refrigerant pipe through which the refrigerant flows. Generates latent heat of evaporation when it evaporates, Low-temperature low-pressure gas refrigerant turned into returns to the compressor, is sent to the condenser becomes compressed again high-temperature and high-pressure gas refrigerant (for example, see Patent Document 1).
The vending machine needs to suppress the maximum power consumption from the viewpoint of power supply capacity or energy saving, and the cooling capacity of the compressor of the refrigerant circuit is limited to the formation of an ice bank in the cooling water tank or to make it compact and inexpensive. The capacity of the auger type ice maker is limited to the ability to make only one of the ice, and when a request to form an ice bank occurs, the first refrigerant valve is opened and the second refrigerant valve is kept closed while the compressor and blower are closed. When a request for ice making occurs, the first refrigerant valve is kept closed and the second refrigerant valve is opened to operate the compressor and the blower to make ice.

For example, if the ice storage amount of the auger type ice making machine is more than a predetermined amount and the ice bank amount of the cooling water tank is less than the predetermined amount, the first refrigerant valve is opened while the compressor and the blower are started and the second refrigerant valve is closed at the same time. The high-temperature and high-pressure gas refrigerant compressed by the compressor becomes a low-temperature and high-pressure liquid refrigerant in the condenser, and the low-temperature and low-pressure liquid refrigerant that has passed through the first refrigerant valve and expanded in the capillary tube is expanded by the cooling water evaporator. It evaporates and the ice bank is increased by the latent heat of vaporization. In this way, when the ice bank amount exceeds a predetermined amount, the compressor and the blower are stopped, and at the same time, the first refrigerant valve is closed. In addition, when the ice storage amount of the auger type ice making machine is less than the predetermined amount, the compressor and the blower are started, and at the same time the first refrigerant valve is closed and the second refrigerant valve is opened, so that the second refrigerant valve passes and expands. The low-temperature and low-pressure liquid refrigerant squeezed and expanded by the valve evaporates in the ice making machine evaporator, and the latent heat of evaporation causes the drinking water supplied from the drinking water tank to icing on the inner wall surface of the ice making cylinder. The auger is rotated and scraped up and pushed up and compressed by an extrusion head to produce ice. When the amount of stored ice exceeds a predetermined amount, the compressor and blower are stopped and the second refrigerant valve is also closed.
In addition, when the ice bank formation request and the ice making request occur simultaneously, the compressor and the blower are operated to open the first refrigerant valve and the second refrigerant valve alternately, and the ice bank formation of the cooling water tank and the auger type ice making machine are performed. The ice making is alternately performed, and when the ice bank amount and the ice storage amount exceed a predetermined amount, the compressor and the blower are stopped and the refrigerant valve is closed at the same time.
JP-A-8-287345

After the operation of the compressor is stopped, the refrigerant line connecting the refrigerant discharge side of the compressor and the first refrigerant valve and the second refrigerant valve is closed in a high pressure state, and the first refrigerant valve and the second refrigerant valve The refrigerant line connecting the two refrigerant valves and the refrigerant suction side of the compressor is closed in a low pressure state.
However, if the differential pressure between the refrigerant discharge side and the suction side of the compressor is large in this way, a large starting torque is required for the motor of the compressor, so that a starting failure occurs. When such a starting failure of the compressor is repeated. There is a risk of damaging the compressor. Thus, when a large starting torque is required for the motor of the compressor, the compressor becomes large and expensive.
In view of the above circumstances, an object of the present invention is to provide a highly reliable and inexpensive refrigerant circuit.

In order to achieve the above object, a refrigerant circuit according to claim 1 of the present invention includes a compressor that compresses a low-temperature and low-pressure gas refrigerant into a high-temperature and high-pressure gas refrigerant, and a gas refrigerant that is heated to a high temperature and high pressure in the compressor. A condenser that radiates and liquefies to form a low-temperature and high-pressure liquid refrigerant; an evaporator that evaporates the liquid refrigerant liquefied by the condenser to generate latent heat of vaporization and returns the refrigerant as a low-temperature and low-pressure gas refrigerant to the compressor; An on-off valve for supplying liquid refrigerant liquefied by the condenser to the evaporator upstream of each of the evaporators connected in parallel;
When the compressor is operated, at least one of the on-off valves is opened and liquid refrigerant is supplied to the evaporator for operation, and at least one of the on-off valves is opened even when the compressor is stopped. It is characterized by comprising control means for controlling.
In the refrigerant circuit according to claim 2 of the present invention, the evaporator connected in parallel in claim 1 described above is an auger type that produces ice by cooling a cooling water tank for cooling syrup and dilution water and drinking water. It is provided in a cup-type vending machine which has an ice making machine and prepares and sells cup beverages.

According to the invention of claim 1, when operating the compressor of the refrigerant circuit, at least one on-off valve is opened to operate by supplying liquid refrigerant to the evaporator, and at least when the operation of the compressor is stopped. By providing a control means for controlling to keep one on-off valve open, it is easy for the high-pressure refrigerant in the refrigerant circuit to move to the low-pressure side after passing through the refrigerant valve after stopping the operation of the compressor. Therefore, the pressure on the refrigerant discharge side and the suction side of the compressor can be reliably balanced in a short time. If the pressure balance between the refrigerant discharge side and the suction side can be reliably maintained in a short time after the operation of the compressor is stopped, the motor load at the start of operation of the compressor can be reliably reduced. Can be prevented, and the reliability of the refrigerant circuit can be improved without fear of damaging the compressor. Further, since a large starting torque is not required for the electric motor of the compressor, the electric motor can be downsized, and the compressor can be downsized to provide a highly reliable and inexpensive refrigerant circuit.
According to the invention of claim 2, it is possible to reduce the size of the compressor of the refrigerant circuit provided in the cup type vending machine that prepares and sells the cup beverage, thereby increasing the reliability and reducing the cost. Become.

Exemplary embodiments of a refrigerant circuit according to the present invention will be explained below in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments.
FIG. 1 is a conceptual view in which a cup-type vending machine includes a refrigerant circuit according to an embodiment of the present invention. As shown in FIG. 1, the refrigerant circuit 1 includes a compressor 2 that compresses a low-temperature and low-pressure gas refrigerant as a working medium into a high-temperature and high-pressure gas refrigerant, and a gas that is compressed by the compressor 2 to become a high-temperature and high-pressure gas. The refrigerant is radiated by heat exchange with the air sent by the operation of the blower 5, and is liquefied to form a low-temperature and high-pressure liquid refrigerant. A dryer 6 that removes and purifies moisture, a T-type fitting 7 that distributes liquid refrigerant to the refrigerant lines 9 and 22, and liquid refrigerant that has been liquefied by the condenser 4 when the valve is opened, flows to the refrigerant line 9. The first refrigerant valve 8 that is supplied to the cooling water evaporator 12 via the capillary tube 11 and the low-temperature and high-pressure liquid refrigerant liquefied by the condenser 4 are squeezed and expanded to reduce the pressure, thereby reducing the low-temperature and low-pressure liquid refrigerant. In the cooling water W of the capillary tube 11 and the cooling water tank 10 The temperature of the cooling water W is brought to approximately 0 ° C. by heat exchange with the ice bank B (ice soul) that has been immersed in the surrounding area by the latent heat of vaporization (heat of vaporization) generated when the liquid refrigerant is evaporated. The cooling water evaporator 12 to be maintained, and the second refrigerant which is supplied to the ice making machine evaporator 25 through the expansion valve 24 by allowing the liquid refrigerant liquefied by the condenser 4 to flow through the refrigerant pipe 22 when the valve is opened. Self-sealing quick couplings 22a and 23a that detachably connect the valve 21 and the refrigerant pipes 22 and 23, and a low-temperature and high-pressure liquid refrigerant liquefied by the condenser 4 are expanded and expanded to reduce the pressure. An expansion valve 24 that is a low-pressure liquid refrigerant and a drinking water tank (not shown) are wound around the outer peripheral surface of the ice making cylinder of the auger type ice making machine 20 and the latent heat of vaporization (heat of vaporization) generated when the liquid refrigerant is evaporated. Evaporation for ice making machines that allow drinking water supplied from 25, and self-sealing quick couplings 26a and 27a for detachably connecting refrigerant pipes 26 and 27 for returning the low-temperature and low-pressure gas refrigerant evaporated and gasified by the ice making machine evaporator 25 to the compressor 2. The T-type fitting 13 for joining the gas refrigerant to be returned to the compressor 2 from the cooling water evaporator 12 and the ice making machine evaporator 25, and the gas refrigerant and oil are the cooling water evaporator 12 and the ice making machine evaporator 25. A check valve 15 for preventing the refrigerant from flowing backward, an accumulator 16 for storing the liquid refrigerant that could not be evaporated by the cooling water evaporator 12 and the ice making machine evaporator 25 and preventing the refrigerant from flowing into the compressor 2; And a refrigerant pipe 14 for returning the gas refrigerant merged at the T-type fitting 13 to the compressor 2 via the check valve 15 and the accumulator 16, and the refrigerant flows in the direction of the arrow in the figure.

FIG. 2 is a block diagram showing a control system of the refrigerant circuit 1. As shown in the figure, the control unit (control means) 90 is provided with a memory 91, a timer 92, and the like. The control unit 90 is a predetermined command signal stored in the memory 91, a timer 92, and an ice bank that is icing on the peripheral area of the cooling water evaporator 12 immersed in the cooling water W of the cooling water tank 10. An ice bank sensor 93 that detects the B amount and outputs a detection signal outputs a signal based on an input signal from the ice storage sensor 94 that detects the ice storage amount of the auger ice making machine 20 and outputs a detection signal; The compressor 2, the blower 5, and the auger type ice making machine 20 are operated, and the first refrigerant valve 8 and the second refrigerant valve 21 are opened and closed.
With this configuration, the operation of the refrigerant circuit 1 of the present invention will be described. Ice bank B in which the signal output from the ice storage sensor 94 of the auger type ice making machine 20 indicates an ice storage amount of a predetermined amount or more and the signal output from the ice bank sensor 93 of the cooling water tank 10 is less than the predetermined amount. The controller 90 starts the operation of the compressor 2 and the blower 5 and opens the first refrigerant valve 8 while the second refrigerant valve 21 is closed, so that the compressor 90 is compressed at the high temperature and high pressure. The gas refrigerant thus obtained becomes a low-temperature and high-pressure liquid refrigerant in the condenser 4, and the low-temperature and low-pressure liquid refrigerant that has passed through the first refrigerant valve 8 and squeezed and expanded in the capillary tube 11 evaporates in the cooling water evaporator 12. Increase ice bank B by latent heat. In this way, the amount of ice bank B increases, and the signal output from ice bank sensor 93 indicates an amount of ice bank B that is greater than or equal to a predetermined amount, while ice storage amount sensor 94 of auger type ice making machine 20 outputs. When the signal indicates an ice storage amount equal to or less than a predetermined amount, the first refrigerant valve 8 is closed and the second refrigerant valve 21 is opened, so that the low-temperature and low-pressure liquid that has passed through the second refrigerant valve 21 and is expanded by the expansion valve 24 is expanded. The refrigerant evaporates in the ice making machine evaporator 25, and the latent heat of evaporation causes the drinking water supplied from the drinking water tank (not shown) to land on the inner wall surface of the ice making cylinder. When the ice bank sensor 93 and the ice storage amount sensor 94 output a signal exceeding a predetermined amount for both the ice bank B amount and the ice storage amount when the ice bank sensor 93 and the ice storage amount sensor 94 output a signal exceeding a predetermined amount, the control unit 90 Compressor 2 and blower The continued opening of the second coolant valve 21 even after stopping the operation, a predetermined time A (e.g., 10 minutes) elapses Closing second refrigerant valve 21 (see Figure 3 (a)).

As described above, if the second refrigerant valve 21 is opened for a predetermined time A even after the operation of the compressor 2 is stopped, after the operation of the compressor 2 is stopped, the high-pressure refrigerant in the refrigerant circuit 1 causes the second refrigerant valve 21 to open. Since it becomes easy to pass and move to the low pressure side, the pressure on the refrigerant discharge side and the suction side of the compressor 2 can be reliably balanced in a short time. If the pressure balance between the refrigerant discharge side and the suction side can be reliably maintained in a short time after the operation of the compressor 2 is stopped, the electric motor load at the start of the operation of the compressor 2 can be reliably reduced. The starting failure of the compressor 2 can be prevented, the risk of damaging the compressor 2 can be eliminated, and the reliability of the refrigerant circuit 1 can be improved. Moreover, since a large starting torque is not required for the electric motor of the compressor 2, the electric motor can be reduced in size, and the compressor 2 can be reduced in size and the inexpensive refrigerant circuit 1 can be provided.
Note that when the ice bank sensor 93 and the ice storage amount sensor 94 output a signal exceeding a predetermined amount for both the ice bank B amount and the ice storage amount, the second refrigerant valve 21 is kept open even after the operation of the compressor 2 and the blower 5 is stopped. In the embodiment, the second refrigerant valve 21 is closed when the predetermined time A has elapsed. However, the signals output from the ice bank sensor 93 and the ice storage amount sensor 94 indicate that the ice bank B amount and the ice storage amount both exceed the predetermined amount. When the operation of the compressor 2 and the blower 5 is stopped, the second refrigerant valve 21 may be closed and the first refrigerant valve 8 may be opened for a predetermined time A (see FIG. 3B). Even in this case, after the operation of the compressor 2 is stopped, it becomes easy for the high-pressure refrigerant in the refrigerant circuit 1 to pass through the first refrigerant valve 8 and move to the low-pressure side. The pressure on the side and suction side can be reliably balanced in a short time. If the pressure balance between the refrigerant discharge side and the suction side can be reliably maintained in a short time after the operation of the compressor 2 is stopped, the electric motor load at the start of the operation of the compressor 2 can be reliably reduced. The starting failure of the compressor 2 can be prevented, the risk of damaging the compressor 2 can be eliminated, and the reliability of the refrigerant circuit 1 can be improved. Moreover, since a large starting torque is not required for the electric motor of the compressor 2, the electric motor can be reduced in size, and the compressor 2 can be reduced in size and the inexpensive refrigerant circuit 1 can be provided.

Further, after the signals output from the ice bank sensor 93 and the ice storage amount sensor 94 indicate that the ice bank B amount and the ice storage amount are equal to or greater than a predetermined amount and the operation of the compressor 2 and the blower 5 is stopped, the first refrigerant valve 8 and The second refrigerant valve 21 may be opened for a predetermined time A (see FIG. 3C). This makes it easy for the high-pressure refrigerant in the refrigerant circuit 1 to pass through the first refrigerant valve 8 and the second refrigerant valve 21 and quickly move to the low-pressure side after the operation of the compressor 2 is stopped. The refrigerant discharge side and suction side pressures of the compressor 2 can be reliably balanced in a shorter time. If the pressure balance between the refrigerant discharge side and the suction side can be reliably maintained in a shorter time after the operation of the compressor 2 is stopped, the electric motor load at the start of the operation of the compressor 2 can be reliably reduced. Therefore, the starting failure of the compressor 2 can be prevented, the risk of damaging the compressor 2 can be eliminated, and the reliability of the refrigerant circuit 1 can be improved. Moreover, since a large starting torque is not required for the electric motor of the compressor 2, the electric motor can be reduced in size, and the compressor 2 can be reduced in size and the inexpensive refrigerant circuit 1 can be provided.
When the ice bank B formation request of the cooling water tank 10 and the ice making request of the auger type ice making machine 20 are generated at the same time, the compressor 2 and the blower 5 are operated to alternately switch the first refrigerant valve 8 and the second refrigerant valve 21. When the ice bank B formation and ice making are alternately performed and the ice bank B amount and the ice storage amount are equal to or larger than the predetermined amount and the operation of the compressor 2 and the blower 5 is stopped, as described above, The refrigerant valve that is open when the compressor 2 and the blower 5 are stopped is continuously opened and closed when a predetermined time A elapses. Alternatively, the opened refrigerant valve is closed and the other refrigerant valve is opened for a predetermined time A. Further, the opened refrigerant valve and other refrigerant valves may be opened A for a predetermined time.

It is the schematic which shows the refrigerant circuit in embodiment of this invention. It is the block diagram which showed the control system of the refrigerant circuit shown in FIG. It is a timing chart which shows control of the control part of the refrigerant circuit shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Refrigerant circuit 2 Compressor 4 Condenser 5 Blower 8 First refrigerant valve 10 Cooling water tank 11 Capillary tube 12 Evaporator for cooling water 20 Auger ice making machine 21 Second refrigerant valve 24 Expansion valve 25 Evaporator for ice making machine 90 Control part (Control means)
93 Ice bank sensor 94 Ice storage sensor

Claims (2)

A compressor that compresses a low-temperature and low-pressure gas refrigerant into a high-temperature and high-pressure gas refrigerant; a condenser that dissipates and liquefies the high-temperature and high-pressure gas refrigerant in the compressor to form a low-temperature and high-pressure liquid refrigerant; The liquid refrigerant liquefied by the evaporator is evaporated to generate latent heat of evaporation, and returned to the compressor as a low-temperature and low-pressure gas refrigerant, and liquefied by the condenser upstream of each of the evaporators connected in parallel. In a refrigerant circuit provided with an on-off valve that supplies liquid refrigerant to the evaporator,
When the compressor is operated, at least one of the on-off valves is opened and liquid refrigerant is supplied to the evaporator for operation, and at least one of the on-off valves is opened even when the compressor is stopped. A refrigerant circuit comprising control means for controlling the refrigerant. The evaporator connected in parallel is provided in a cup vending machine that prepares and sells cup beverages with a cooling water tank that cools syrup and dilution water and an auger type ice maker that cools drinking water and produces ice. The refrigerant circuit according to claim 1, wherein the refrigerant circuit is provided.

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