JP6614250B2 - Ice making system - Google Patents

Description

  The present disclosure relates to ice making systems.

  Patent Document 1 discloses an ice making refrigeration apparatus including a double-tube-type full-liquid evaporator having an inner tube for circulating a medium to be cooled and an outer tube that houses the inner tube. In this ice making refrigeration apparatus, the high-pressure liquid refrigerant flowing out from the condenser is expanded by the expansion mechanism to reduce the pressure, and the low-pressure liquid refrigerant is supplied into the outer cooling chamber between the inner pipe and the outer pipe of the full liquid evaporator. . As a result, the medium to be cooled flowing through the inner pipe is cooled, while the liquid refrigerant in the outer cooling chamber evaporates. The to-be-cooled medium in the inner tube becomes slurry-like ice when the supercooling is released by the rotating blade. The low-pressure refrigerant evaporated in the outer cooling chamber is discharged from the full liquid evaporator and returned to the suction side of the compressor.

  Furthermore, the ice-making refrigeration apparatus described in Patent Document 1 includes a gas-liquid separator between the full liquid evaporator and the suction side of the compressor. In the ice making refrigeration apparatus described in Patent Document 1, since the refrigerant discharged from the full liquid evaporator becomes wet vapor, the refrigerant is separated into a gas phase and a liquid phase by a gas-liquid separator, and only the gas phase is obtained. The compressor is sucking.

JP 2003-185285 A

  The ice-making refrigeration apparatus described in Patent Document 1 includes a gas-liquid separator in order to suppress liquid refrigerant from flowing into the compressor. However, it is difficult to control the wet state of the refrigerant discharged from the full liquid evaporator, that is, the degree of dryness, simply by providing a gas-liquid separator.

  An object of this indication is to provide the ice making system which can control the dryness of the refrigerant | coolant discharged | emitted from a full liquid evaporator.

(1) The ice making system of the present disclosure includes:
A refrigerant circuit in which a compressor, a heat source side heat exchanger, a second expansion mechanism, a liquid receiver, a first expansion mechanism, and a full liquid evaporator are connected in this order by a refrigerant pipe; and the full liquid evaporator An ice making system comprising a circulation circuit for circulating a medium to be cooled that is cooled by
The refrigerant circuit is
The ice making operation and the ice melting operation are connected to the discharge side of the compressor, and the refrigerant discharged from the compressor is switched to either the heat source side heat exchanger side or the full liquid evaporator side to flow. A four-way selector valve that switches between
A first heat transfer pipe disposed in a first refrigerant path between the liquid receiver and the first expansion mechanism, and a second refrigerant path between the full liquid evaporator and the compressor. A superheater that exchanges heat between the refrigerant flowing through the first heat transfer tube and the refrigerant flowing through the second heat transfer tube,
And avoiding means for allowing the refrigerant discharged from the full liquid evaporator during the ice-breaking operation to flow into the liquid receiver while avoiding the first heat transfer tube.

  The ice making system having the above configuration includes the first heat transfer pipe disposed in the first refrigerant path between the first expansion mechanism and the liquid receiver, and the second between the full liquid evaporator and the compressor. A second heat transfer pipe disposed in the refrigerant path, and a superheater that exchanges heat between the refrigerant flowing through the first heat transfer pipe and the refrigerant flowing through the second heat transfer pipe. A desired degree of superheat can be imparted to the wet refrigerant discharged from the liquid evaporator, and the dryness of the refrigerant discharged from the full liquid evaporator can also be appropriately controlled.

  In addition, if ice solidifies and adheres in the full liquid evaporator or the ice slurry stays in the full liquid evaporator, the ice slurry cannot be properly formed. In the system, since the deicing operation in which the high-temperature refrigerant discharged from the compressor by the four-way switching valve is allowed to flow to the full-liquid evaporator side is possible, the ice in the full-liquid evaporator can be melted. During this ice-breaking operation, the refrigerant is condensed in the full-liquid evaporator and flows toward the receiver, but when it passes through the first heat transfer tube of the superheater, it is heated by the refrigerant flowing through the second heat transfer tube. The liquid refrigerant condensed in the full liquid evaporator becomes a gas-liquid two-phase refrigerant in the superheater, and the possibility that the gas-liquid two-phase refrigerant flows into the liquid receiver increases. In this regard, the ice making system having the above-described configuration includes avoiding means for allowing the refrigerant discharged from the full-liquid evaporator to flow into the liquid receiver while avoiding the first heat transfer tube. Inflow of the two-phase refrigerant can be suppressed.

(2) Preferably, the avoiding means includes a first position between the first heat transfer tube and the first expansion mechanism, and the first heat transfer tube and the liquid receiver in the first refrigerant path. A bypass path bypassing the second position between,
In the ice making operation, the flow of the refrigerant in the bypass path is blocked between the first position and the second position, and in the ice melting operation, the first position is between the first position and the second position. A refrigerant flow control unit that blocks a refrigerant flow in one refrigerant path.
With such a configuration, the refrigerant discharged from the full liquid evaporator can be flowed to the bypass path.

(3) Preferably, the refrigerant flow control unit allows a refrigerant flow from the first position to the second position in the bypass path and blocks a reverse refrigerant flow; and A second check valve that allows a refrigerant flow from the second position to the first position in the first refrigerant path and blocks a reverse refrigerant flow.
With such a configuration, the refrigerant flow can be controlled with a simple configuration.

1 is a schematic configuration diagram of an ice making system according to a first embodiment. It is side surface explanatory drawing of an ice making machine. It is a schematic explanatory drawing which shows the ice making machine and the refrigerant | coolant piping connected to this. It is a schematic block diagram of the ice making system which shows the flow of the refrigerant | coolant in the case of ice making operation. It is explanatory drawing which shows roughly the ice making machine which shows the flow of the refrigerant | coolant at the time of ice making operation, and the refrigerant | coolant piping connected to this. It is a ph diagram which shows a refrigerating cycle. It is a schematic block diagram of the ice making system which shows the flow of the refrigerant | coolant at the time of ice-breaking operation. It is explanatory drawing which shows roughly the ice making machine which shows the flow of the refrigerant | coolant in the case of ice-melting operation, and the refrigerant | coolant piping connected to this. It is a schematic explanatory drawing which shows the ice maker of the ice making system which concerns on 2nd Embodiment, and the refrigerant | coolant piping connected to this. It is explanatory drawing corresponding to FIG. 8 which shows the flow of the refrigerant | coolant when not providing the bypass path | route as a comparative example.

  Hereinafter, embodiments of an ice making system will be described in detail with reference to the accompanying drawings. In addition, this indication is not limited to the following illustrations, is shown by the claim, and intends that all the changes within the meaning and range equivalent to the claim are included.

[First Embodiment]
<Overall configuration of ice making system>
FIG. 1 is a schematic configuration diagram of an ice making system A according to the first embodiment.
The ice making system A of the present embodiment is a system that continuously generates ice slurry from the ice making machine 1 using seawater stored in the seawater tank 8 as a raw material, and returns the generated ice slurry to the seawater tank 8.

The ice slurry means sherbet-like ice in which fine ice is turbid in water or an aqueous solution. The ice slurry is also called slurry ice, ice slurry, slurry ice, slush ice, or liquid ice.
The ice making system A of the present embodiment can continuously generate ice slurry based on seawater. For this reason, the ice making system A of this embodiment is installed in a fishing boat, a fishing port, etc., for example, and the ice slurry returned to the seawater tank 8 is utilized for the cold preservation of fresh fish.

  In addition, the ice making system A of the present embodiment switches between an ice making operation in which ice making is performed in the ice making machine 1 and an ice melting operation in which the ice in the ice making machine 1 is melted.

  The ice making system A uses seawater as a cooling medium. The ice making system A includes an ice making machine 1, which is a use side heat exchanger, a compressor 2, a heat source side heat exchanger 3, a four-way switching valve 4, a use side expansion valve (first expansion mechanism) 5, a superheater 6, and a receiver. (Liquid receiver) 7, a heat source side expansion valve (second expansion mechanism) 27, a blower fan 10, a seawater tank 8, a pump 9, and the like. Further, the ice making system A includes a control device 50.

The compressor 2, the heat source side heat exchanger 3, the heat source side expansion valve 27, the receiver 7, the use side expansion valve 5, the ice making machine 1, and the superheater 6 are connected in this order by the refrigerant pipe to form a refrigerant circuit. ing.
The ice making machine 1, the seawater tank 8, and the pump 9 are connected by seawater piping to form a circulation circuit.

  The four-way switching valve 4 is connected to the discharge side of the compressor 2 and has a function of switching and flowing the refrigerant discharged from the compressor 2 to the heat source side heat exchanger 3 side or the ice making machine 1 side. The four-way switching valve 4 switches between ice making operation and ice melting operation.

  The compressor 2 compresses the refrigerant and circulates the refrigerant in the refrigerant circuit. The compressor 2 is a variable capacity type (variable capacity type). Specifically, the compressor 2 can change the operation rotational speed of this motor stepwise or continuously by inverter-controlling a built-in motor.

The blower fan 10 air-cools the heat source side heat exchanger 3. The blower fan 10 includes a motor whose operation rotational speed is changed stepwise or continuously by inverter control.
The use side expansion valve 5 and the heat source side expansion valve 27 are composed of, for example, a pulse motor drive type electronic expansion valve, and the opening degree thereof can be adjusted.

  The superheater 6 is disposed between the ice making machine 1 and the compressor 2 and superheats the refrigerant discharged from the ice making machine 1. Specifically, the superheater 6 superheats the refrigerant discharged from the ice making machine 1 by the refrigerant flowing out of the heat source side heat exchanger 3 and passing through the receiver 7. In the present embodiment, two superheaters 6 are connected in series. Note that the two superheaters 6 can be connected in parallel. A specific configuration of the superheater 6 will be described later.

FIG. 2 is an explanatory side view of the ice making machine. FIG. 3 is an explanatory view schematically showing an ice making machine and refrigerant piping connected thereto.
The ice making machine 1 is constituted by a double-pipe ice making machine. The ice making machine 1 includes an evaporator 1A and a blade mechanism 15. The evaporator 1A includes an inner tube 12 and an outer tube 13 formed in a cylindrical shape. Moreover, 1 A of evaporators are a horizontal installation type, and the axial center of the inner pipe | tube 12 and the outer pipe | tube 13 is arrange | positioned horizontally.

  The inner pipe 12 is an element through which seawater as a medium to be cooled passes. The inner tube 12 is made of a metal material. Both ends in the axial direction of the inner tube 12 are closed. A blade mechanism 15 is disposed on the inner tube 12. The blade mechanism 15 scrapes and disperses the sherbet-like slurry ice generated on the inner peripheral surface of the inner tube 12 in the inner tube 12.

  A seawater inlet 16 is provided on one axial end side (the right side in FIG. 2) of the inner pipe 12. Seawater is supplied from the seawater inlet 16 into the inner pipe 12. A seawater outlet 17 is provided on the other axial end side of the inner pipe 12 (left side in FIG. 2). Seawater in the inner pipe 12 is discharged from the seawater outlet 17.

  The outer tube 13 is provided coaxially with the inner tube 12 on the radially outer side of the inner tube 12. The outer tube 13 is made of a metal material. One or a plurality (three in this embodiment) of refrigerant inlets 18 are provided in the lower portion of the outer tube 13. One or a plurality (two in this embodiment) of refrigerant outlets 19 are provided in the upper portion of the outer tube 13. An annular space 14 between the inner peripheral surface of the outer tube 13 and the outer peripheral surface of the inner tube 12 is a region into which a refrigerant that exchanges heat with seawater flows. The refrigerant supplied from the refrigerant inlet 18 passes through the annular space 14 and is discharged from the refrigerant outlet 19.

  The blade mechanism 15 includes a rotary shaft 20, a support bar 21, a blade 22, and a drive unit 24. The other end of the rotating shaft 20 in the axial direction extends to the outside from a flange 23 provided at one end of the inner tube 12 in the axial direction, and is connected to a motor as the drive unit 24. Support bars 21 are erected on the circumferential surface of the rotating shaft 20 at predetermined intervals, and a blade 22 is attached to the tip of the support bar 21. The blade 22 is made of, for example, a metal strip member. The side edge on the front side in the rotational direction of the blade 22 has a sharp tapered shape.

  The evaporator 1A of the double-pipe ice making machine 1 is a full liquid evaporator. In the full liquid evaporator 1A, most of the annular space 14 between the outer tube 13 and the inner tube 12 is a liquid refrigerant, thereby improving the heat exchange efficiency between the refrigerant and seawater. Further, since most of the annular space 14 is a liquid refrigerant, the refrigerating machine oil in the full liquid evaporator 1A can be easily discharged from the full liquid evaporator 1A, and the discharged refrigerating machine oil is compressed. By returning to the machine 2, insufficient lubrication of the compressor 2 can be suppressed and reliability can be improved.

  As shown in FIG. 3, the superheater 6 is configured by a double tube heat exchanger. The superheater 6 includes a first heat transfer tube 41 as an outer tube and a second heat transfer tube 42 as an inner tube. The first heat transfer tube 41 is provided in the first refrigerant path R <b> 1 between the receiver 7 and the use side expansion valve 5. The second heat transfer tube 42 is provided in the second refrigerant path R <b> 2 between the compressor 2 and the ice making machine 1. Therefore, during the ice making operation, the refrigerant discharged from the ice making machine 1 and flowing into the second heat transfer pipe 42 of the superheater 6 passes through the heat source side heat exchanger 3 through the heat source side expansion valve 27 and the receiver 7 to the first. The refrigerant is superheated by the refrigerant flowing into the heat transfer tube 41.

  As shown in FIG. 1, the ice making system A of the present embodiment flows the refrigerant discharged from the full liquid evaporator 1 </ b> A into the liquid receiver 7 while avoiding the first heat transfer pipe 41 during the ice melting operation. An avoiding means is provided. This avoiding means includes the first position A1 between the superheater 6 (first heat transfer pipe 41) and the use-side expansion valve 5 in the first refrigerant path R1, and the superheater 6 (first transfer in the first refrigerant path R1). A bypass path B that bypasses between the heat pipe 41) and the second position A2 between the receiver 7 is provided. In addition, the avoiding means includes a first check valve 51 in the bypass path B that allows the refrigerant flow from the first position A1 to the second position A2 and blocks the refrigerant flow opposite thereto. The avoiding means is a refrigerant from the second position A2 to the superheater 6 (first heat transfer pipe 41) between the second position A2 and the superheater 6 (first heat transfer pipe 41) in the first refrigerant path R1. The second check valve 52 is provided to allow the flow of the refrigerant and to block the reverse flow of the refrigerant. These check valves 51 and 52 constitute a refrigerant flow control unit.

  As shown in FIG. 1, the ice making system A includes a control device 50. The control device 50 includes a CPU and a memory. The memory includes RAM, ROM, and the like.

  The control apparatus 50 implement | achieves various control regarding operation | movement of the ice making system A, when CPU runs the computer program stored in memory. Specifically, the control device 50 controls the opening degrees of the use side expansion valve 5 and the heat source side expansion valve 27. Further, the control device 50 controls the operating frequencies of the compressor 2 and the blower fan 10. The control device 50 may be provided separately for the ice making machine 1 side and the heat source side heat exchanger 3 side. In this case, for example, the heat source side expansion valve 27, the blower fan 10, and the compressor 2 are provided. The operation control can be performed by the control device on the heat source side heat exchanger 3 side, and the operation control of the use side expansion valve 5 can be performed by the control device on the ice making machine 1 side.

  The refrigerant circuit in the ice making system A is provided with a plurality of sensors. As shown in FIG. 1, a suction pressure sensor 31 is provided on the suction side of the compressor 2, and a discharge pressure sensor 32 is provided on the discharge side. A gas refrigerant temperature sensor 34 is provided on the downstream side of the superheater 6 after passing through the ice making machine 1. The ice making machine 1 is provided with a current sensor 35 that detects the current value of the drive unit 24. Detection signals from these sensors are input to the control device 50 and used for various controls.

<Operation of ice making system>
(Ice making operation)
FIG. 4 is a schematic configuration diagram of the ice making system showing the flow of the refrigerant during the ice making operation. FIG. 5 is an explanatory view schematically showing an ice making machine showing the flow of the refrigerant during the ice making operation and refrigerant piping connected to the ice making machine.
In order to perform a normal ice making operation, the four-way switching valve 4 is maintained in a state indicated by a solid line in FIG. The high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the heat source side heat exchanger 3 functioning as a condenser through the four-way switching valve 4, and exchanges heat with air by the operation of the blower fan 10 to condense and liquefy. To do. The liquefied refrigerant flows through the heat source side expansion valve 27 in the fully opened state, and flows to the first heat transfer tube 41 of the superheater 6 through the receiver 7. At this time, since the first check valve 51 is provided in the bypass path B branched from the first refrigerant path R1, the refrigerant does not pass through the bypass path B, and the first heat transfer pipe 41 of the superheater 6 is passed through. Inflow. The refrigerant that has passed through the first heat transfer pipe 41 flows to the use side expansion valve 5.

The refrigerant is decompressed to a predetermined low pressure by the use side expansion valve 5 to become a gas-liquid two-phase refrigerant, and an inner pipe 12 and an outer pipe 13 constituting the ice making machine 1 from the refrigerant inlet 18 (see FIG. 2) of the ice making machine 1. In the annular space 14 between the two.
The refrigerant supplied into the annular space 14 evaporates by exchanging heat with the seawater introduced into the inner pipe 12 by the pump 9. The pump 9 sucks seawater from the seawater tank 8 and pumps the seawater into the seawater passage of the ice making machine 1. The ice slurry generated in the seawater channel is returned to the seawater tank 8 together with seawater by the pump pressure.

  The refrigerant evaporated in the ice making machine 1 passes through the second refrigerant path R2 and is sucked into the compressor 2 through the second heat transfer tube 42 of the superheater 6. The superheater 6 superheats the refrigerant discharged from the ice making machine 1 and flowing through the second heat transfer tube 42 with the refrigerant flowing through the first heat transfer tube 41. This is because the refrigerant discharged from the ice making machine 1 is in a wet state, and if it is sucked into the compressor 2 as it is, the compressor 2 breaks down due to a sudden increase in pressure (liquid compression) inside the cylinder or a decrease in the viscosity of the refrigerating machine oil. It is a cause. Hereinafter, the relationship between the wet state of the refrigerant discharged from the ice making machine 1 and overheating will be described.

FIG. 6 is a ph diagram showing the refrigeration cycle.
In the ice making system A of the present embodiment, the dryness of the refrigerant discharged from the refrigerant outlet 19 of the full liquid evaporator 1A in order to keep the liquid refrigerant liquid level in the annular space 14 of the full liquid evaporator 1A high. x is configured to fall within a predetermined target range of less than 1, for example, x = 0.9 to 0.95. The superheater 6 gives the superheat degree SH to the refrigerant discharged from the refrigerant outlet 19 of the full liquid evaporator 1 </ b> A, thereby suppressing the inflow of the liquid refrigerant into the compressor 2. The superheater 6 has a capability of giving a superheat degree SH of 5 to 8 degrees to a refrigerant having a dryness x of 0.9 to 0.95.

The control device 50 of the present embodiment performs the following process in order to keep the dryness of the refrigerant discharged from the full liquid evaporator 1A within a predetermined range.
The control device 50 according to the present embodiment calculates the refrigerant saturation temperature (evaporation temperature) based on the suction pressure detected by the suction pressure sensor 31. Moreover, the control apparatus 50 calculates | requires superheat degree SH of a refrigerant | coolant by the difference of the temperature detected by the gas refrigerant temperature sensor 34, and saturation temperature. The control device 50 compares the degree of superheat SH with a predetermined target value (target degree of superheat), and controls the opening of the use side expansion valve 5 so that they match. Specifically, the control device 50 causes the superheater 6 to keep the dryness x of the refrigerant discharged from the full liquid evaporator 1A within a predetermined range (for example, a range of x = 0.9 to 0.95). The degree of opening of the use-side expansion valve 5 is controlled so that the superheat degree SH that can be given is given to the refrigerant.

  Thereby, in the annular space 14 of the full liquid evaporator 1A, the liquid level of the liquid refrigerant can be kept constant at a high position, and the heat exchange efficiency between the liquid refrigerant and seawater can be increased. In addition, the refrigeration oil that has flowed into the full liquid evaporator 1 </ b> A is discharged from the full liquid evaporator 1 </ b> A together with the wet refrigerant and easily returns to the compressor 2. Therefore, insufficient lubrication of the compressor 2 can be suppressed.

(Ice melting operation)
As a result of the ice making operation as described above, the ice solidifies and adheres to the inner tube 12, and the blade 22 of the blade mechanism 15 is caught by the ice, resulting in a large rotational load (this phenomenon is also referred to as “ice rock”). ) Or a phenomenon in which the flow of seawater in the inner pipe 12 of the ice making machine 1 stagnates and ice slurry accumulates in the inner pipe 12 (this phenomenon is also referred to as “ice accumulation”) occurs. It becomes difficult to continue driving 1. In this case, an ice removal operation (cleaning operation) is performed in order to melt the ice in the inner tube 12.

  As shown in FIG. 1, the control device 50 constantly monitors the current value from the current sensor 35, and performs a process of switching from the ice making operation to the ice breaking operation when the current value exceeds a predetermined threshold value. Specifically, the control device 50 controls the four-way switching valve 4 to be switched to a state indicated by a broken line in FIG.

FIG. 7 is a schematic configuration diagram of the ice making system showing the flow of the refrigerant during the ice melting operation. FIG. 8 is an explanatory diagram schematically showing an ice making machine showing the flow of the refrigerant during the ice-breaking operation and refrigerant piping connected to the ice making machine.
The high-temperature gas refrigerant discharged from the compressor 2 passes through the four-way switching valve 4 and the second heat transfer pipe 42 of the superheater 6, and the annular space between the inner pipe 12 and the outer pipe 13 of the full liquid evaporator 1 </ b> A. 14 and flows into the inner pipe 12 to be condensed and liquefied by exchanging heat with seawater containing ice. At this time, the ice in the inner tube 12 is heated by the refrigerant to defrost. The liquid refrigerant discharged from the full liquid evaporator 1 </ b> A passes through the fully-open use side expansion valve 5, and then flows from the first refrigerant path R <b> 1 to the bypass path B and flows into the receiver 7. At this time, since the second check valve 52 is provided in the first refrigerant path R1, the liquid refrigerant is suppressed from flowing into the first heat transfer tube 41 of the superheater 6. Therefore, in the superheater 6, it can suppress that a liquid refrigerant is heated.

  This point will be described in detail with reference to FIG. FIG. 10 is an explanatory diagram corresponding to FIG. 8 illustrating the flow of the refrigerant when the bypass path is not provided as a comparative example. In FIG. 10, the liquid refrigerant discharged from the ice making machine 1 flows into the first heat transfer pipe 41 of the superheater 6 after passing through the use side expansion valve 5 in the fully opened state. Since the high-temperature gas refrigerant discharged from the compressor 2 flows through the second heat transfer pipe 42 of the superheater 6, the liquid refrigerant in the first heat transfer pipe 41 is heated to become a gas-liquid two-phase refrigerant. When the gas-liquid two-phase refrigerant flows into the receiver 7, the proportion of the liquid refrigerant in the refrigerant in the receiver 7 decreases, and the amount of refrigerant flowing into the heat source side heat exchanger 3 decreases. Therefore, the capability of the heat source side heat exchanger 3 as an evaporator is reduced. Further, the high-temperature gas refrigerant flowing from the compressor 2 through the second heat transfer pipe 42 of the superheater 6 is cooled by the refrigerant flowing through the first heat transfer pipe 41, and the temperature is lowered. For this reason, the ice making capacity of the ice making machine 1 is reduced.

On the other hand, in the ice making system A of the present embodiment, as shown in FIG. 8, the refrigerant circuit includes the bypass path B and the check valves 51 and 52, so that the above disadvantages do not occur and the efficiency is increased. The ice-free operation can be performed well.
In FIG. 7 and FIG. 8, the refrigerant discharged from the receiver 7 is decompressed by the heat source side expansion valve 27, evaporates in the heat source side heat exchanger 3, and is sucked into the compressor 2.

[Second Embodiment]
FIG. 9 is a schematic explanatory view showing an ice making machine of the ice making system according to the second embodiment and refrigerant piping connected thereto.
The ice making system A of the present embodiment includes a flow path switching valve 53 as a refrigerant flow control unit in place of the first and second check valves 51 and 52 of the first embodiment. The flow path switching valve 53 is provided at the second position A2, and the first flow path f1 from the receiver 7 toward the first heat transfer pipe 41 of the superheater 6 and the second flow from the bypass path B toward the receiver 7 are provided. It switches the path f2. When the ice making operation is performed, the control device 50 switches the flow path switching valve 53 to the first flow path f1, and when performing the ice melting operation, the control apparatus 50 switches the flow path switching valve 53 to the second flow path f2. Switch. Thereby, it functions similarly to the check valves 51 and 52 of the first embodiment. The flow path switching valve 53 may be provided at the first position A1.

[Effects of Embodiment]
As described above, the ice making system A of each of the above embodiments includes the compressor 2, the heat source side heat exchanger 3, the heat source side expansion valve 27, the receiver 7, the use side expansion valve 5, and the full liquid evaporator 1A. A refrigerant circuit formed by connecting the refrigerant pipes in this order and a circulation circuit for circulating the cooling medium cooled by the full liquid evaporator 1A are provided. The refrigerant circuit further includes a four-way switching valve 4 and a superheater 6. The four-way switching valve 4 is connected to the discharge side of the compressor 2 and switches the refrigerant discharged from the compressor 2 to either the heat source side heat exchanger 3 side or the full liquid evaporator 1A side to flow. Switch between ice making and ice melting. The superheater 6 is connected to the first heat transfer pipe 41 disposed in the first refrigerant path R1 between the receiver 7 and the use side expansion valve 5 and the second refrigerant path R2 between the ice making machine 1 and the compressor 2. The second heat transfer tube 42 is provided, and heat exchange is performed between the refrigerant flowing through the first heat transfer tube 41 and the refrigerant flowing through the second heat transfer tube 42. The refrigerant circuit further includes avoidance means. The avoiding means causes the refrigerant discharged from the full liquid evaporator 1 </ b> A to flow into the receiver 7 while avoiding the first heat transfer tube 41.

With the configuration as described above, the ice making system A of the present embodiment can give a superheat degree to the refrigerant discharged from the ice making machine 1 by the superheater 6 during the ice making operation. The wet state of the refrigerant discharged from the evaporator 1A can also be controlled appropriately.
When performing the ice-breaking operation, the high-temperature liquid refrigerant that has passed through the ice making machine 1 flows into the receiver 7 without passing through the first heat transfer pipe 41 of the superheater 6. The phase refrigerant does not flow in, the liquid refrigerant ratio in the receiver 7 is suppressed from decreasing, and a sufficient amount of refrigerant can be flowed into the heat source side heat exchanger 3.

The avoiding means includes a bypass path B and refrigerant flow control units 51 and 52. The bypass path B includes a first position A1 between the first heat transfer pipe 41 and the use side expansion valve 5 and a second position A2 between the first heat transfer pipe 41 and the receiver 7 in the first refrigerant path R1. Bypass. The refrigerant flow control units 51 and 52 block the flow of refrigerant in the bypass path B between the first position A1 and the second position A2 in the ice making operation, and the first position A1 and the first position in the ice breaking operation. The flow of the refrigerant in the first refrigerant path is blocked between the second position A2.
With such a configuration, it is possible to flow the refrigerant discharged from the full liquid evaporator 1 </ b> A through the bypass path and suppress the refrigerant from being heated by the superheater 6.

  Further, in the ice making system A of the first embodiment, the refrigerant flow control unit allows the refrigerant flow from the first position A1 to the second position A2 in the bypass path B and blocks the reverse refrigerant flow. 1 check valve 51 and a second check valve 52 that allows the refrigerant flow from the second position A2 to the first position A1 in the first refrigerant path R1 and blocks the reverse refrigerant flow, The configuration for suppressing the liquid refrigerant discharged from the ice making machine 1 from flowing into the first heat transfer pipe 41 of the superheater 6 during the ice-melting operation can be simplified.

[Other variations]
The present disclosure is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims.
For example, in the first embodiment, the second check valve 52 is provided between the second position A2 in the first refrigerant path R1 and the superheater 6 (first heat transfer pipe 41). You may be provided between the container 6 (1st heat exchanger tube 41) and 1st position A1. Further, instead of the first and second check valves 51 and 52, an opening / closing valve such as an electromagnetic valve controlled to open / close by the control device 50 may be provided.

  In the embodiment described above, a double-pipe type was used as the full-vapor evaporator of the ice making machine. For example, a plurality of inner pipes through which the medium to be cooled flows are provided inside the outer pipe through which the refrigerant flows. It may be a configuration. Moreover, in the said embodiment, although the ice making machine was one, you may connect the several ice making machine in series. Moreover, in the said embodiment, although the compressor was one, you may connect a several compressor in parallel.

1: Ice maker 2: Compressor 3: Heat source side heat exchanger 4: Four-way switching valve 5: Use side expansion valve (first expansion mechanism)
6: Superheater 7: Receiver (receiver)
27: Heat source side expansion valve (second expansion mechanism)
41: 1st heat transfer pipe 42: 2nd heat transfer pipe 51: 1st check valve 52: 2nd check valve 53: Flow path switching valve A: Ice making system A1: 1st position A2: 2nd position B: Bypass path R1: First refrigerant path R2: Second refrigerant path

Claims (3)

The compressor (2), the heat source side heat exchanger (3), the second expansion mechanism (27), the liquid receiver (7), the first expansion mechanism (5), and the full liquid evaporator (1A) are arranged in this order. An ice making system comprising a refrigerant circuit connected by a refrigerant pipe and a circulation circuit for circulating a medium to be cooled cooled by the full liquid evaporator (1A),
The refrigerant circuit is
Connected to the discharge side of the compressor (2), the refrigerant discharged from the compressor (2) is transferred to either the heat source side heat exchanger (3) side or the full liquid evaporator (1A) side. A four-way selector valve (4) for switching between ice making operation and ice melting operation by switching and flowing;
A first heat transfer pipe (41) disposed in a first refrigerant path (R1) between the liquid receiver (7) and the first expansion mechanism (5), and the full liquid evaporator (1A) And a second heat transfer pipe (42) disposed in a second refrigerant path (R2) between the compressor (2) and the refrigerant flowing through the first heat transfer pipe (41) and the second heat transfer pipe ( 42) a superheater (6) for exchanging heat with the refrigerant flowing through
Avoiding means for causing the refrigerant discharged from the full-vapor evaporator (1A) to flow into the liquid receiver (7) while avoiding the first heat transfer pipe (41) during the ice-breaking operation; Equipped ice making system. The avoiding means includes a first position (A1) between the first heat transfer tube (41) and the first expansion mechanism (5) in the first refrigerant path (R1), and the first heat transfer tube ( 41) and a bypass path (B) that bypasses the second position (A2) between the receiver (7),
In the ice making operation, the refrigerant flow in the bypass path (B) is prevented between the first position (A1) and the second position (A2). In the ice breaking operation, the first position (A1) ) And the second position (A2), the ice making system according to claim 1, further comprising a refrigerant flow control unit that blocks a refrigerant flow in the first refrigerant path (R1). The refrigerant flow control unit allows a refrigerant flow from the first position (A1) to the second position (A2) in the bypass path (B) and prevents a reverse refrigerant flow. the valve (51), a second to prevent the flow of acceptable refrigerant reverse the flow of the refrigerant of the to the in the first refrigerant path (R1) the second position (A2) or al the first position (A1) The ice making system according to claim 2, comprising a check valve (52).

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