Cold Fruit Manufacturing Equipment

Abstract

To provide a frozen confectionery manufacturing apparatus capable of cooling water for cooling a cooling medium discharged from a compressor without imposing a load on a device for manufacturing chiller water.SOLUTION: A frozen confectionery manufacturing apparatus includes: an evaporator 5 for manufacturing frozen confectionery by cooling a raw material by bringing a cooling medium in a liquid state into a gaseous state; a compressor 2 for compressing the cooling medium in a gaseous state; a condenser 3 for condensing the cooling medium compressed by the compressor 2 using chiller water; and a cooling device 70 for cooling chiller water.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a frozen dessert manufacturing apparatus. [Background technology]

[0002] As a conventional technique, Patent Document 1 discloses a refrigerator in which a compressor, a gas cooler, an expansion valve, and an evaporator are connected in this order by refrigerant piping. The gas cooler exchanges heat between the high-temperature, high-pressure refrigerant discharged from the compressor and the outside air ventilated by a gas cooler fan, thereby dissipating heat from the refrigerant. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-090103 Summary of the Invention [Problem to be solved by the invention]

[0004] In frozen dessert manufacturing equipment, the high-temperature, high-pressure refrigerant discharged from the compressor is cooled by chiller water. The temperature of the chiller water plays an important role in determining the refrigerant condensation temperature of the equipment, so proper temperature management is necessary. In such a situation, if the refrigeration capacity of the equipment can be used to optimize the temperature of the chiller water, it will contribute to stabilizing the refrigerant management of the equipment. An object of the present invention is to provide a frozen dessert manufacturing apparatus that can cool water that cools a refrigerant discharged from a compressor without imposing a burden on the chiller water manufacturing apparatus. [Means for solving the problem]

[0005] The present invention, which was completed with this objective in mind, is a frozen dessert manufacturing apparatus that includes a manufacturing unit that produces frozen desserts by cooling ingredients by converting a liquid refrigerant into a gaseous state, a compressor that compresses the gaseous refrigerant, a condenser that condenses the refrigerant compressed by the compressor using chiller water, and a cooling device that cools the chiller water. Here, the cooling device may include a heat exchanger that exchanges heat between the chiller water and the liquid refrigerant. The liquid refrigerant used for heat exchange in the heat exchanger may be a refrigerant that has been liquefied in the condenser and then expanded to reduce its pressure. The cooling device may also have an expansion valve that expands the refrigerant that has been liquefied in the condenser to reduce its pressure, and the manufacturing section cools the raw materials by covering the cylinder into which the raw materials have been injected with the refrigerant whose pressure has been reduced by the expansion valve, and the cooling device may have a branch path that branches off from the flow path from the expansion valve to the manufacturing section and supplies the refrigerant whose pressure has been reduced by the expansion valve to the heat exchanger. The refrigerant after heat exchange in the heat exchanger may be merged with the refrigerant flowing from the production section to the compressor. Carbon dioxide may also be used as the refrigerant. [Effects of the Invention]

[0006] According to the present invention, the device can cool the water that cools the refrigerant discharged from the compressor without imposing the burden of strengthening or expanding the equipment for producing chiller water. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram showing an example of a schematic configuration of a frozen dessert manufacturing apparatus to which the present embodiment is applied. [Figure 2] 1(a) and 1(b) are diagrams showing an example of the configuration of a stirring device to which the present embodiment is applied. [Figure 3] FIG. 2 is a diagram illustrating an example of a schematic configuration of a control device. [Figure 4]5 is a flowchart illustrating an example of a frequency change process performed by a compressor control unit. [Figure 5] 10 is a flowchart showing an example of a process for changing the opening degree of a hot gas valve performed by a hot gas control unit. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a diagram showing an example of a schematic configuration of a frozen dessert producing apparatus 1 to which the present embodiment is applied. The frozen dessert production apparatus 1 is used to produce frozen desserts such as ice creams and frozen desserts. The frozen dessert production apparatus 1 of this embodiment is equipped with a mixing device 100 that mixes and cools an ingredient mix, which is a mixture of frozen dessert ingredients and air. The configuration of the mixing device 100 will be described in detail later.

[0009] 1, the frozen dessert production apparatus 1 includes a compressor 2, a condenser 3, an expansion valve 4, an evaporator 5, an accumulator 6, a heat exchanger 7, and a receiver 8. The frozen dessert production apparatus 1 also includes a circular refrigerant circuit 51 that connects the compressor 2, the condenser 3, the expansion valve 4, the evaporator 5, the accumulator 6, the heat exchanger 7, the receiver 8, etc. The frozen dessert production apparatus 1 uses carbon dioxide refrigerant (hereinafter, may be referred to as "CO2 refrigerant") as a refrigerant. CO2 refrigerant has a lower global warming potential than fluorocarbon refrigerants. By using CO2 refrigerant, the frozen dessert production apparatus 1 aims to reduce the environmental impact compared to apparatuses that use other refrigerants.

[0010] Furthermore, the frozen dessert producing apparatus 1 has a branch path 52 that branches off from the piping between the compressor 2 and the condenser 3 in the refrigerant circuit 51 and has an end connected to the evaporator 5. In addition, the frozen dessert manufacturing apparatus 1 is provided with a hot gas valve 9 on the branch path 52 that adjusts the amount of high-temperature, high-pressure gaseous refrigerant (hereinafter sometimes referred to as "hot gas") compressed by the compressor 2 that flows into the evaporator 5. The frozen dessert manufacturing apparatus 1 also includes a well-known separator 11 that separates oil for lubricating the compressor 2 from the refrigerant flowing out of the compressor 2, and a well-known return section 12 that has a filter that removes foreign matter from the oil separated by the separator 11. The frozen dessert producing apparatus 1 also includes an oil supplying device 20 that returns oil that has entered the evaporator 5 to the compressor 2.

[0011] The frozen dessert manufacturing apparatus 1 also includes an evaporation pressure sensor 31 that detects the pressure of the gaseous refrigerant in the accumulator 6, a liquid level sensor 32 that detects the liquid level of the liquid refrigerant in the evaporator 5, and a receiver pressure sensor 33 that detects the pressure of the refrigerant in the receiver 8. The frozen dessert manufacturing apparatus 1 also includes a low-pressure side safety valve 35 that releases the refrigerant to the outside of the frozen dessert manufacturing apparatus 1 when the pressure of the refrigerant in the accumulator 6 exceeds a predetermined upper limit value, and a high-pressure side safety valve 36 that releases the refrigerant to the outside of the frozen dessert manufacturing apparatus 1 when the pressure of the refrigerant in the receiver 8 exceeds a predetermined upper limit value. The frozen dessert producing apparatus 1 also includes a control device 60 that controls each part of the frozen dessert producing apparatus 1. The frozen dessert producing apparatus 1 also includes a cooling device 70 that cools chiller water used by the condenser 3 to condense the refrigerant compressed by the compressor 2. The elements constituting the frozen dessert producing apparatus 1 will be described in more detail below.

[0012] The compressor 2 draws in a refrigerant through a suction port 2a, compresses it, and discharges it from a discharge port 2b. This causes the compressor 2 to circulate the refrigerant within a refrigerant circuit 51. The compressor 2 has a motor 2c as a drive source, and the operating frequency is continuously adjusted by controlling the motor 2c using a control device 60. Examples of the compressor 2 include, but are not limited to, a so-called rotary compressor that compresses the refrigerant by rotating a piston using the motor 2c, and a so-called reciprocating compressor that compresses the refrigerant by reciprocating a piston using the motor 2c. The operating frequency of the compressor 2 refers to the number of times (number of rotations, number of reciprocations) that a moving body, such as a piston, driven by the motor 2c in the compressor 2 moves per unit time (e.g., one second).

[0013] The condenser 3 condenses and liquefies the refrigerant compressed by the compressor 2 by heat exchange with chiller water cooled to a predetermined temperature by the cooling device 70. In this embodiment, a CO2 refrigerant is used, which has a higher pressure when in a gaseous state than fluorocarbon refrigerants, so chilled water is used as chiller water to further cool the refrigerant discharged from the compressor 2.

[0014] The expansion valve 4 reduces the pressure of the refrigerant condensed in the condenser 3 and expands it. The expansion valve 4 in this embodiment is a so-called motor valve, having a valve (not shown) that opens and closes a flow path through which the refrigerant flows, and a motor 4a that drives the valve to open and close. Based on the control of the control device 60, the motor 4a is driven to rotate the valve, thereby adjusting the rotation angle of the valve (hereinafter, sometimes referred to as the "opening degree") and changing the flow path area through which the refrigerant can flow. When the valve opening degree is 0 degrees, the valve is fully closed and the flow path area is 0, and when the valve opening degree is at the maximum opening degree, the valve is fully open and the flow path area is maximum. The valve opening degree is continuously adjusted between 0 degrees and the maximum opening degree. This continuously adjusts the amount of refrigerant that passes through the expansion valve 4 and is supplied to the evaporator 5.

[0015] The evaporator 5 is provided inside the above-mentioned mixing device 100. The evaporator 5 evaporates the refrigerant expanded by the expansion valve 4 by heat exchange with the ingredient mix of the frozen dessert supplied to the cylinder inner tube 110 (described later) of the mixing device 100. In addition, in the mixing device 100, the ingredient mix is ​​cooled by the refrigerant in the evaporator 5 to produce the frozen dessert. The accumulator 6 separates the gaseous refrigerant evaporated in the evaporator 5 from the liquid refrigerant. The accumulator 6 then returns the separated liquid refrigerant to the evaporator 5, thereby preventing the liquid refrigerant from flowing into the compressor 2.

[0016] The heat exchanger 7 exchanges heat between the refrigerant that has been evaporated in the evaporator 5 and passed through the accumulator 6, and the refrigerant that has been condensed in the condenser 3 and discharged from the receiver 8. In addition, the heat exchanger 7 heats the refrigerant that has passed through the accumulator 6 with the high-temperature refrigerant discharged from the receiver 8, and if any liquid refrigerant remains in the refrigerant that has passed through the accumulator 6, the heat exchanger 7 vaporizes the remaining liquid refrigerant and prevents the liquid refrigerant from flowing into the compressor 2. The receiver 8 stores a portion of the liquid refrigerant condensed in the condenser 3 and supplies the stored refrigerant to the expansion valve 4.

[0017] The hot gas valve 9 supplies the hot gas discharged from the compressor 2 to the evaporator 5 via a branch line 52. The hot gas valve 9 has a motor 9a that drives the valve to open and close. The opening of the hot gas valve 9 is continuously adjusted based on the control of the motor 9a by the control device 60. This continuously adjusts the flow rate of the hot gas supplied to the evaporator 5 by the hot gas valve 9.

[0018] The evaporation pressure sensor 31 detects the pressure in the pipes between the evaporator 5 and the accumulator 6 and the low-pressure side safety valve 35, thereby detecting the pressure of the gaseous refrigerant in the evaporator 5 and the accumulator 6. The receiver pressure sensor 33 detects the pressure in the piping between the receiver 8 and the high-pressure side safety valve 36, thereby detecting the pressure of the gaseous refrigerant that has evaporated from the liquid refrigerant in the receiver 8.

[0019] The liquid level sensor 32 detects the liquid level of the refrigerant in a space S2 (see FIGS. 2(a) and 2(b)) between an inner cylinder 110 and an outer cylinder 120 (described later) of the agitator 100 as the liquid level of the refrigerant in the evaporator 5. The liquid level sensor 32 is not particularly limited as long as it can continuously detect the liquid level of the refrigerant, and for example, a capacitance type liquid level sensor can be used. The detection result by the liquid level sensor 32 is output to the control device 60.

[0020] Next, a description will be given of the behavior of the refrigerant in the frozen dessert production apparatus 1 of this embodiment. In the frozen dessert production apparatus 1 of this embodiment, a refrigeration cycle is formed in which the refrigerant flows in order through the compressor 2, the condenser 3, the receiver 8, a separation heat exchanger 22 (described later), the heat exchanger 7, the expansion valve 4, the evaporator 5, the accumulator 6, and the heat exchanger 7, before returning to the compressor 2. Specifically, in the frozen dessert production apparatus 1, a high-temperature, high-pressure gaseous refrigerant compressed by the compressor 2 and discharged from the discharge port 2b flows into the condenser 3. In the condenser 3, the refrigerant exchanges heat with chiller water cooled to a predetermined temperature, where it is condensed and liquefied, and then discharged from the condenser 3. The high-pressure liquid refrigerant discharged from the condenser 3 passes through the receiver 8, the separating heat exchanger 22, and the heat exchanger 7. The refrigerant flowing from the receiver 8 into the heat exchanger 7 is used to heat and vaporize the refrigerant flowing from the accumulator 6 to the compressor 2. The high-pressure liquid refrigerant discharged from the heat exchanger 7 is then decompressed by the expansion valve 4, becoming a low-temperature, low-pressure, two-phase gas-liquid refrigerant, which then flows into the evaporator 5. In the evaporator 5, the refrigerant exchanges heat with the raw material mix, where it is evaporated and vaporized, and then discharged from the evaporator 5. The low-pressure gaseous refrigerant discharged from the evaporator 5 passes through the accumulator 6 and the heat exchanger 7, and is then sucked into the compressor 2 through the suction port 2a, where it is compressed again.

[0021] Furthermore, in the frozen dessert production apparatus 1, a high-temperature, high-pressure gaseous refrigerant (hot gas) compressed by the compressor 2 and discharged from the discharge portion 2b passes through the branch path 52 and is supplied to the hot gas valve 9. Then, depending on the pressure of the evaporator 5, the hot gas is supplied directly to the evaporator 5 by the hot gas valve 9.

[0022] (Agitator 100) Next, the configuration of the agitator 100 will be described. Figures 2(a) and 2(b) are diagrams showing an example of the configuration of the agitator 100 to which this embodiment is applied. Figure 2(a) is a diagram showing the agitator 100 as seen from the side, and Figure 2(b) is a cross-sectional view taken along line IIB-IIB in Figure 2(a). 2(a)-(b), the stirring device 100 includes a cylindrical inner cylinder 110 to which an ingredient mix for a frozen dessert is supplied, and a cylindrical outer cylinder 120 that is provided outside the cylinder inner cylinder 110 and through which a refrigerant is supplied to a space formed between the cylinder inner cylinder 110 and the outer cylinder 120. The stirring device 100 also includes a stirring unit 130 that is provided in the internal space of the cylinder inner cylinder 110 and stirs the ingredient mix supplied to the internal space of the cylinder inner cylinder 110.

[0023] In the frozen dessert producing apparatus 1 of the present embodiment, the inner cylinder 110 and the outer cylinder 120 of the stirring device 100 constitute the evaporator 5 described above. In addition, in the agitator 100 of this embodiment, the inner cylinder 110 and the outer cylinder 120 are arranged so that their central axes are substantially horizontal.

[0024] As described above, the raw material mix is ​​supplied to the internal space S1 of the cylinder inner tube 110. Then, in the cylinder inner tube 110, the raw material mix is ​​stirred and cooled in the space S1 to produce a finished frozen dessert. The cylinder inner tube 110 has an ingredient supply port 111, which is provided at one end in the axial direction, through which the ingredient mix is ​​supplied toward the space S1, and a frozen dessert discharge port 112, which is provided at the other end in the axial direction, through which the produced frozen dessert is discharged from the space S1. The ingredient mix is ​​stored in an ingredient tank (not shown), and is supplied to the space S1 via the ingredient supply port 111 by an ingredient supply pump. The frozen dessert produced in the space S1 is discharged from the space S1 into a frozen dessert tank (not shown) via the frozen dessert discharge port 112 by a discharge pump while maintaining a constant pressure inside the cylinder inner tube 110.

[0025] The cylinder inner tube 110 also has an ingredient temperature sensor 114 that measures the temperature of the ingredient mix supplied to the ingredient supply port 111. The cylinder inner tube 110 also has a frozen dessert temperature sensor 115 that measures the temperature of the frozen dessert discharged from the frozen dessert discharge port 112. The temperature measurement results from the ingredient temperature sensor 114 and the frozen dessert temperature sensor 115 are output to the control device 60 (see FIG. 1).

[0026] As described above, the cylinder outer cylinder 120 is disposed outside the cylinder inner cylinder 110, and a low-temperature, low-pressure refrigerant in a gas-liquid two-phase state expanded by the expansion valve 4 (see FIG. 1) is supplied to the space S2 formed between the cylinder outer cylinder 120 and the outer peripheral surface of the cylinder inner cylinder 110. In the cylinder outer cylinder 120, for example, the refrigerant is supplied so that the liquid level is higher than the vertically upper part of the outer peripheral surface of the cylinder inner cylinder 110. Then, in the cylinder outer cylinder 120, heat exchange occurs between this refrigerant and the raw material mix supplied to the space S1 of the cylinder inner cylinder 110, and the refrigerant evaporates.

[0027] Here, in the stirring device 100 of this embodiment, the central axis of the cylinder inner tube 110 and the central axis of the cylinder outer tube 120 are arranged so as to be offset from each other. Specifically, as shown in Fig. 2(b), the central axis of the cylinder inner tube 110 is arranged so as to be offset vertically downward from the central axis of the cylinder outer tube 120. This makes it possible to reduce the amount of refrigerant required to cool the cylinder inner tube 110 and to increase the evaporation area of ​​the refrigerant, thereby enabling more efficient heat exchange, compared to when the central axes of the cylinder inner tube 110 and the cylinder outer tube 120 are aligned, for example.

[0028] The cylinder outer cylinder 120 has a refrigerant supply port 121 through which the low-temperature, low-pressure refrigerant in a gas-liquid two-phase state expanded by the expansion valve 4 is supplied toward the space S2, and a refrigerant discharge port 122 through which the gaseous refrigerant evaporated by heat exchange is discharged. The refrigerant discharged from the refrigerant discharge port 122 flows into the accumulator 6 (see FIG. 1). Furthermore, the cylinder outer cylinder 120 has a hot gas supply port 123 through which high-temperature gaseous refrigerant (hot gas) is supplied toward the space S2 by the hot gas valve 9. Furthermore, the cylinder outer cylinder 120 has a refrigerant suction port 124 through which the liquid refrigerant is drawn into the oil supply device 20.

[0029] The refrigerant supply port 121, the refrigerant discharge port 122, the hot gas supply port 123, and the refrigerant suction port 124 are provided on the outer peripheral surface of the cylinder outer cylinder 120. In this example, the refrigerant supply port 121 is provided vertically downward on the outer peripheral surface of the cylinder outer cylinder 120. Two refrigerant discharge ports 122 are provided vertically upward on the outer peripheral surface of the cylinder outer cylinder 120. The hot gas supply port 123 is provided on the outer peripheral surface of the cylinder outer cylinder 120 in the center of the cylinder outer cylinder 120. The hot gas supply port 123 is provided vertically above the refrigerant supply port 121 and vertically below the refrigerant discharge port 122. The refrigerant suction port 124 is provided vertically above the refrigerant supply port 121 and in the center of the cylinder outer cylinder 120.

[0030] As described above, the agitating unit 130 agitates the raw material mix supplied to the space S1 within the cylinder inner tube 110. The agitating unit 130 includes a cylindrical support portion 131 extending axially within the space S1 within the cylinder inner tube 110, and a plurality of blades 132 provided on the outer peripheral surface of the support portion 131. The agitating unit 130 also includes a rotating shaft 133 extending axially from one end and the other end of the support portion 131 and rotatably supported via bearings 139 at both ends of the cylinder inner tube 110. The agitating unit 130 also includes a motor 135 that rotates the rotating shaft 133 at a predetermined rotation speed under the control of the control device 60, and a load sensor 136 that detects the rotation load of the rotating shaft 133 applied by the motor 135. Here, in the stirring device 100 of this embodiment, the stirring unit 130 is disposed so that the central axis thereof substantially coincides with the central axis of the cylinder inner tube 110. In addition, in the stirring device 100, the stirring unit 130 is disposed substantially in the center of the cylinder inner tube 110.

[0031] In the stirring unit 130, the rotation shaft 133 is rotationally driven by the motor 135, so that the support unit 131 and the blade 132 rotate and move in the space S1 inside the cylinder inner tube 110. Then, in the space S1, the blade 132 scrapes off deposits adhering to the inner wall surface of the cylinder inner tube 110, while stirring the raw material mix.

[0032] (Oil supply device 20) The oil supplying device 20 supplies oil into the refrigerant flowing into the compressor 2. Here, the refrigerant used in the frozen dessert production apparatus 1 is a CO2 refrigerant, and therefore, in the temperature range in which it exists in the space S2, the oil completely dissolves in the refrigerant, making it difficult to separate the oil from the refrigerant. Furthermore, if the refrigerant in the space S2 contains a large amount of oil, heat exchange between the refrigerant containing a large amount of oil and the ingredient mix in the cylinder inner tube 110 may be hindered. In consideration of the above, the oil supply device 20 is provided within the frozen dessert manufacturing apparatus 1, and pulls the refrigerant in the space S2 mixed with oil out of the cylinder outer tube 120, separates the refrigerant and oil, and supplies the oil into the refrigerant flowing into the compressor 2.

[0033] The oil supplying device 20 has an ejector 21 that sucks refrigerant from the space S2, and a separation heat exchanger 22 that separates the oil from the refrigerant (containing oil) sucked by the ejector 21. The oil supplying device 20 has a secondary branching path 54 that branches off from the branching path 52 upstream of the hot gas valve 9 and has an end connected to the ejector 21. The oil supplying device 20 also has a suction path 55 that connects the space S2 and the ejector 21 and allows the refrigerant in the space S2 to flow toward the ejector 21. The oil supplying device 20 also has an inflow path 56 that connects the ejector 21 and the separation heat exchanger 22 and allows the refrigerant flowing out of the ejector 21 to flow into the separation heat exchanger 22. The oil supply device 20 also has an outflow path 58 that connects the separation heat exchanger 22 to a pipe 57 between the heat exchanger 7 and the compressor 2, and allows the refrigerant flowing out of the separation heat exchanger 22 to flow into the pipe 57.

[0034] The ejector 21 has a nozzle portion 21a through which the refrigerant pressurized by the compressor 2 passes, and a suction portion 21b that draws in the refrigerant in the cylinder outer tube 120. In this ejector 21, the refrigerant pressurized by the compressor 2 flows in through the inlet of the nozzle portion 21a, then reduces its pressure and expands as the flow path area decreases, and flows out after its flow rate increases. Meanwhile, the refrigerant in the cylinder outer tube 120 is drawn in through the inlet of the suction portion 21b due to the pressure difference between the inlet of the suction portion 21b and the nozzle portion 21a, and is drawn into the refrigerant pressurized by the compressor 2. The two refrigerants mix and flow out of the ejector 21. The behavior of the refrigerant in the ejector 21 utilizes the Venturi effect.

[0035] The refrigerant flowing out from the ejector 21 exchanges heat with the high-pressure liquid refrigerant condensed in the condenser 3 in the separation heat exchanger 22 and is vaporized. This separates the refrigerant from the oil, and the separated oil flows into the pipe 57 arranged upstream of the compressor 2 via the outlet path 58. In this way, the oil is extracted from the refrigerant in the space S2 and injected into the gaseous refrigerant upstream of the compressor 2.

[0036] (Control device 60) FIG. 3 is a diagram showing an example of a schematic configuration of the control device 60. As shown in FIG. The control device 60 has a CPU (Central Processing Unit) (not shown), a ROM (Read Only Memory) (not shown), a RAM (Random Access Memory) (not shown), etc. The ROM stores a basic program (operating system) executed by the CPU, various settings, etc. The CPU uses the RAM as a working area and executes application programs read from the ROM or a storage unit (not shown) such as a semiconductor memory or an HDD (Hard Disk Drive). The functions of the control device 60 described below are realized by the CPU executing the programs.

[0037] The control device 60 receives output signals from the evaporation pressure sensor 31, the liquid level sensor 32, and the like. The control device 60 includes a compressor control unit 61 that controls the frequency F, which is the operating frequency of the compressor 2, a hot gas control unit 62 that controls the opening degree of the hot gas valve 9, and an expansion valve control unit 63 that controls the opening degree of the expansion valve 4.

[0038] The control device 60 starts the raw material supply pump to store the raw material mix in the cylinder inner tube 110, and starts the agitator 100. Then, the compressor 2 is started at a predetermined frequency, and the hot gas valve 9 is set to a predetermined opening. This causes the temperature of the raw material mix in the cylinder inner tube 110 to drop and hardening begins. When the motor load of the agitator 100 reaches a predetermined load setting (hereinafter, sometimes referred to as "pump start"), the raw material supply pump and discharge pump start (hereinafter, sometimes referred to as "storage and initial freezing").

[0039] Furthermore, in the control device 60, when a frozen dessert is produced (hereinafter sometimes referred to as "during production"), the compressor control unit 61 controls the frequency F of the compressor 2, and the hot gas control unit 62 controls the opening of the hot gas valve 9, thereby adjusting the temperature of the frozen dessert produced in the mixing device 100. Furthermore, during production, the expansion valve control unit 63 controls the opening of the expansion valve 4, thereby adjusting the liquid level of the liquid refrigerant in the evaporator 5.

[0040] Furthermore, in order to prevent liquid refrigerant from remaining in the evaporator 5 at the end of production, the control device 60 closes the expansion valve 4, drives the compressor 2, and recovers the refrigerant liquefied in the condenser 3 into the receiver 8. To this end, the control device 60 controls each device while detecting the pressure of the refrigerant in the evaporator 5 and the accumulator 6 and the height of the liquid refrigerant surface in the evaporator 5. Hereinafter, operation of the frozen dessert production apparatus 1 under this control may be referred to as "refrigerant recovery operation at the end of production." This is because if liquid refrigerant remains in the evaporator 5 when production is stopped, the pressure in the evaporator 5 and accumulator 6 increases, causing the refrigerant to be released from the low-pressure side safety valve 35, which is dangerous.

[0041] Furthermore, when no frozen desserts are being produced, the control device 60 detects the pressure inside the evaporator 5 and accumulator 6 using the evaporation pressure sensor 31, and when the detected pressure reaches a predetermined upper limit pressure, starts the compressor 2 at a predetermined frequency, and when the detected pressure drops to a predetermined lower limit pressure, stops the compressor 2. Hereinafter, operation of the frozen dessert production apparatus 1 under this control may be referred to as "pressure maintenance operation when production is stopped." When the evaporation pressure rises when production is stopped, the control device 60 repeatedly starts and stops the compressor 2 under the above control.

[0042] The control performed by the control device 60 during production, the control of the refrigerant recovery operation when production is completed, and the control of the pressure maintenance operation when production is stopped will be described in detail below. (Manufacturing control) In the frozen dessert production apparatus 1, when the operating frequency of the compressor 2 is increased, gaseous refrigerant flows from the evaporator 5 and the accumulator 6 into the compressor 2, causing a decrease in the pressure of the refrigerant in the evaporator 5. Furthermore, when the operating frequency of the compressor 2 is reduced, the flow of gaseous refrigerant from the evaporator 5 and the accumulator 6 into the compressor 2 is inhibited, causing a rise in the pressure of the refrigerant in the evaporator 5. Furthermore, in the evaporator 5, the refrigerant has the property that the temperature increases as the pressure increases, and the temperature decreases as the pressure decreases. In the frozen dessert manufacturing apparatus 1 of this embodiment, based on this relationship, the frequency of the compressor 2 is controlled based on the pressure of the refrigerant in the evaporator 5 and accumulator 6 detected by the evaporation pressure sensor 31, and the opening of the hot gas valve 9 is also controlled, thereby controlling the temperature of the refrigerant within a predetermined range.

[0043] The compressor control unit 61 controls the frequency F of the compressor 2 based on the pressure P of the gaseous refrigerant in the accumulator 6 detected by the evaporation pressure sensor 31. In other words, the compressor control unit 61 controls the frequency F of the compressor 2 based on the pressure of the gaseous refrigerant evaporated in the evaporator 5. More specifically, when the pressure P detected by the evaporation pressure sensor 31 becomes higher than a predetermined set evaporation pressure Px, the compressor control unit 61 increases the rotation speed of the motor 2c to increase the frequency F of the compressor 2. On the other hand, when the pressure P detected by the evaporation pressure sensor 31 becomes lower than the set evaporation pressure Px, the compressor control unit 61 decreases the rotation speed of the motor 2c to decrease the frequency F of the compressor 2. However, the compressor control unit 61 rotates the compressor 2 within a predetermined frequency range.

[0044] The hot gas control unit 62 reduces the opening of the hot gas valve 9 when the pressure P detected by the evaporation pressure sensor 31 is equal to or higher than the set evaporation pressure Px. On the other hand, when the pressure P detected by the evaporation pressure sensor 31 is lower than the set evaporation pressure Px, the hot gas control unit 62 increases the opening of the hot gas valve 9. Thereafter, when the pressure P detected by the evaporation pressure sensor 31 becomes equal to the set evaporation pressure Px, the hot gas control unit 62 maintains the opening of the hot gas valve 9.

[0045] FIG. 4 is a flowchart showing an example of the frequency change process performed by the compressor control unit 61. The compressor control unit 61 repeatedly executes the frequency change process at predetermined intervals (for example, every 1 millisecond). The compressor control unit 61 determines whether the pressure P detected by the evaporation pressure sensor 31 is equal to the set evaporation pressure Px (S401). If the pressure P is not equal to the set evaporation pressure Px (No in S401), the compressor control unit 61 determines whether the pressure P detected by the evaporation pressure sensor 31 is greater than the set evaporation pressure Px (S402). If the pressure P is greater than the set evaporation pressure Px (Yes in S402), the compressor control unit 61 increases the frequency F of the compressor 2 (S403). Thereafter, the compressor control unit 61 performs the processing of S401.

[0046] On the other hand, if the pressure P is not higher than the set evaporation pressure Px (No in S402), the compressor control unit 61 reduces the frequency F of the compressor 2 (S404). Thereafter, the compressor control unit 61 performs the process of S401. If the pressure P is equal to the set evaporation pressure Px (Yes in S401), the compressor control unit 61 maintains the frequency F of the compressor 2 (S405).

[0047] FIG. 5 is a flowchart showing an example of processing for changing the opening degree of the hot gas valve 9 performed by the hot gas control unit 62. The hot gas control unit 62 repeatedly executes the opening degree changing process at predetermined intervals (for example, every 1 millisecond). The hot gas control unit 62 determines whether the pressure P detected by the evaporation pressure sensor 31 is equal to the set evaporation pressure Px (S501). If the pressure P is not equal to the set evaporation pressure Px (No in S501), the hot gas control unit 62 determines whether the pressure P detected by the evaporation pressure sensor 31 is greater than the set evaporation pressure Px (S502). If the pressure P is greater than the set evaporation pressure Px (Yes in S502), the hot gas control unit 62 reduces the opening of the hot gas valve 9 (S503). Thereafter, the hot gas control unit 62 performs the processing of S501.

[0048] On the other hand, if the pressure P is not greater than the set evaporation pressure Px (No in S502), the hot gas control unit 62 increases the opening of the hot gas valve 9 (S504). Thereafter, the hot gas control unit 62 performs the process of S501. If the pressure P is equal to the set evaporation pressure Px (Yes in S501), the hot gas control unit 62 maintains the opening of the hot gas valve 9 (S505).

[0049] In this way, in the control device 60, the compressor control unit 61 adjusts the frequency of the compressor 2, and the hot gas control unit 62 adjusts the opening of the hot gas valve 9, thereby controlling the pressure of the gaseous refrigerant evaporated in the evaporator 5 to the set evaporation pressure Px. Since the refrigerant has the characteristic that the temperature increases as the pressure increases in the evaporator 5 and the temperature decreases as the pressure decreases, the control device 60 controls the refrigerant temperature to a predetermined value by controlling the refrigerant pressure to a predetermined value. This controls the temperature of the frozen dessert produced by the mixing device 100 to a predetermined value.

[0050] As described above, in the frozen dessert production apparatus 1, the hot gas control unit 62 adjusts the opening degree of the hot gas valve 9 based on the state of the evaporator 5, more specifically, based on the pressure of the gaseous refrigerant evaporated in the evaporator 5. As a result, the opening degree of the hot gas valve 9 changes depending on the state of the evaporator 5, and the amount of hot gas supplied to the evaporator 5 varies. Here, consider the case where the hot gas valve 9 is a solenoid valve that fully closes the refrigerant flow path when it is off and fully opens the refrigerant flow path when it is on. If the hot gas valve 9 is a solenoid valve, when it is turned on from a state in which the refrigerant flow path is fully closed when it is off and the flow path is fully opened, a large amount of hot gas flows into the evaporator 5 all at once. On the other hand, when the solenoid valve is turned off from a state in which the refrigerant flow path is fully open when it is on and the flow path is fully closed, hot gas no longer flows into the evaporator 5. As a result, the hot gas flowing into the evaporator 5 fluctuates greatly when the solenoid valve is switched on and off, and the pressure too This can cause large fluctuations in the temperature of frozen desserts. In contrast, in the frozen dessert production apparatus 1 according to the present embodiment, the opening of the hot gas valve 9 gradually changes depending on the state of the evaporator 5, so that the amount of liquid refrigerant flowing into the evaporator 5 gradually fluctuates. As a result, the pressure of the gaseous refrigerant in the evaporator 5 gradually fluctuates, and fluctuations in the temperature of the frozen dessert are suppressed.

[0051] In particular, in the frozen dessert producing apparatus 1 according to the present embodiment, when the pressure P detected by the evaporation pressure sensor 31 is greater than the set evaporation pressure Px (Yes in S402, Yes in S502), the compressor control unit 61 increases the frequency F of the compressor 2 (S403), and the hot gas control unit 62 decreases the aperture of the hot gas valve 9 (S503). On the other hand, when the pressure P detected by the evaporation pressure sensor 31 is less than the set evaporation pressure Px (No in S402, No in S502), the compressor control unit 61 decreases the frequency F of the compressor 2 (S404), and the hot gas control unit 62 increases the aperture of the hot gas valve 9 (S504). As a result, for example, even when the flow rate of the ingredient mix supplied to the stirring device 100 is small or when producing a frozen dessert such as soft serve ice cream, which has a high optimum temperature, the frozen dessert can be kept at an appropriate temperature.

[0052] The expansion valve control unit 63 controls the opening degree of the expansion valve 4 using the detected height h, which is the height of the liquid level of the liquid refrigerant in the evaporator 5 detected by the liquid level sensor 32. When the detected height h is higher than a predetermined set height hx, the expansion valve control unit 63 reduces the opening degree of the expansion valve 4 to decrease the amount of liquid refrigerant supplied to the evaporator 5. On the other hand, when the detected height h is lower than the set height hx, the expansion valve control unit 63 increases the opening degree of the expansion valve 4 to increase the amount of liquid refrigerant supplied to the evaporator 5.

[0053] In this way, the expansion valve control unit 63 controls the opening degree of the expansion valve 4 so that the liquid level of the liquid refrigerant becomes a predetermined set height hx. The lower limit height hn is set to the height of the lowest surface of the liquid refrigerant in the evaporator 5. The upper limit height hm is set to the height of the liquid refrigerant at the upper limit of the liquid level sensor.

[0054] In the frozen dessert production apparatus 1 configured as described above, when the liquid refrigerant in the evaporator 5 vaporizes and the liquid level of the liquid refrigerant drops, the expansion valve control unit 63 increases the opening of the expansion valve 4. The expansion valve 4 is a so-called motor valve, and as the opening of the valve gradually increases, the amount of refrigerant that passes through the expansion valve 4 and is supplied to the evaporator 5 gradually increases. Here, if there is a large amount of liquid refrigerant in the evaporator 5, the cooling of the frozen dessert is more easily promoted, and if there is little liquid refrigerant in the evaporator 5, the cooling of the frozen dessert is less promoted. Consider a case where the expansion valve 4 is a solenoid valve that fully closes the refrigerant flow path when it is off and fully opens the refrigerant flow path when it is on. If the expansion valve 4 is a solenoid valve, when the expansion valve 4 is turned on and the flow path is fully opened from a state in which the refrigerant flow path is fully closed, a large amount of liquid refrigerant flows into the evaporator 5 all at once. On the other hand, when the solenoid valve is turned off and the refrigerant flow path is fully opened from a state in which the solenoid valve is on and the flow path is fully closed, the liquid refrigerant no longer flows into the evaporator 5. As a result, the amount of liquid refrigerant flowing into the evaporator 5 fluctuates greatly when the solenoid valve is switched on and off, which tends to cause large fluctuations in the temperature of the frozen dessert. In contrast, in the frozen dessert production apparatus 1 according to the present embodiment, the opening of the expansion valve 4 changes gradually, so that the amount of liquid refrigerant flowing into the evaporator 5 changes gradually. As a result, the temperature of the frozen dessert also changes little.

[0055] (Refrigerant recovery operation at the end of production) At the end of production, the refrigerant present in the evaporator 5 is collected in the receiver 8. When a user performs a predetermined operation to end production during production (for example, when the stop button is pressed), the control device 60 closes the expansion valve 4 and stops the raw material supply pump and the discharge pump. The control device 60 also causes the compressor 2 to continue operating at a predetermined frequency. The control device 60 also causes the agitator 100 to continue operating at a predetermined constant frequency. Then, the control device 60 closes the hot gas valve 9 when the detected height h detected by the liquid level sensor 32 drops to a predetermined height. In addition, when the pressure of the refrigerant in the evaporator 5 and the accumulator 6 detected by the evaporation pressure sensor 31 drops to a predetermined pressure, the control device 60 stops the compressor 2 and the agitator 100.

[0056] At the end of production, the refrigerant is not evaporated by the evaporator 5 and the heat of evaporation is not consumed, so if refrigerant remains in the evaporator 5, the temperature of the remaining refrigerant rises. Here, if a large amount of refrigerant remains in the evaporator 5, the refrigerant pressure is likely to increase as the temperature rises. In contrast, in the frozen dessert production apparatus 1 of this embodiment, the refrigerant remaining in the evaporator 5 is recovered in the receiver 8 at the end of production, which makes it difficult for the refrigerant pressure to rise.

[0057] Furthermore, when production is completed, the control device 60 does not stop the supply of chiller water to the condenser 3, but continues the supply as it did during production. As a result, the refrigerant collected in the receiver 8 is cooled by the condenser 3, and the temperature of the receiver 8 is maintained at a low temperature, so that the pressure of the refrigerant in the receiver 8 is unlikely to increase. After the production of the frozen dessert is stopped, the hot gas control unit 62 may increase the opening of the hot gas valve 9 to a value greater than 0 to supply hot gas into the stirring device 100 until the raw material mix in the cylinder inner tube 110 melts.

[0058] (Pressure maintenance operation when production is stopped) After the refrigerant recovery is complete, the compressor control unit 61 controls the compressor 2 based on the pressure P of the gaseous refrigerant in the accumulator 6 detected by the evaporation pressure sensor 31. More specifically, as described above, the compressor control unit 61 stops the rotation of the motor 2c after the refrigerant recovery is complete. Then, when the pressure P detected by the evaporation pressure sensor 31 becomes higher than a predetermined upper limit pressure Py, the compressor control unit 61 rotates the motor 2c. Then, when the pressure P detected by the evaporation pressure sensor 31 becomes equal to or lower than a predetermined lower limit pressure Pm, the compressor control unit 61 stops the rotation of the motor 2c. The compressor control unit 61 continues to perform the above control during the period when the production of frozen desserts is stopped.

[0059] Incidentally, when production is stopped, the refrigerant present in the evaporator 5 and accumulator 6 is recovered in the receiver 8 as described above, but it is difficult to recover all of the refrigerant, and some refrigerant may remain in the evaporator 5 and accumulator 6. Because the refrigerant used in the frozen dessert production apparatus 1 is a CO2 refrigerant, even if the refrigerant is recovered in the receiver 8, the pressure of the refrigerant is likely to increase due to the passage of time since production of the frozen dessert was stopped, an increase in the ambient temperature of the frozen dessert production apparatus 1, etc. Furthermore, when production is stopped, so-called CIP (Cleaning In Place) cleaning may be performed, in which sterilizing water heated to a predetermined temperature is supplied to the space S1 of the cylinder inner tube 110 to clean it. Since the temperature of the sterilizing water used in CIP cleaning is high, at approximately 85°C, if refrigerant remains in the evaporator 5, the pressure of the refrigerant may rise suddenly. If the pressure of the refrigerant becomes excessively high, there is a risk that the refrigerant will be released to the outside of the frozen dessert producing apparatus 1 via the low-pressure side safety valve 35.

[0060] In contrast, in this embodiment, when the pressure P detected by the evaporation pressure sensor 31 becomes higher than a predetermined upper limit pressure Py, the compressor 2 is operated to recover the refrigerant present in the evaporator 5 and the accumulator 6 into the receiver 8. This reduces the refrigerant pressure in the evaporator 5 and the accumulator 6, suppressing a rise in the refrigerant pressure. As a result, the refrigerant is prevented from being released to the outside of the frozen dessert production apparatus 1 via the low-pressure side safety valve 35. Furthermore, when the pressure P detected by the evaporation pressure sensor 31 becomes lower than a predetermined lower limit pressure Pm, the operation of the compressor 2 is stopped, thereby reducing power consumption when production is stopped.

[0061] (Cooling device 70) Cooling device 70 includes a cooling heat exchanger 71 that cools chiller water by exchanging heat between the chiller water and the refrigerant. Cooling device 70 also includes a branch path 72 that branches off from a pipe between expansion valve 4 and evaporator 5 and supplies liquid refrigerant that has been decompressed and expanded by expansion valve 4 to cooling heat exchanger 71. Cooling device 70 also includes a merging path 73 that merges the refrigerant discharged from cooling heat exchanger 71 with refrigerant heading toward compressor 2 between accumulator 6 and heat exchanger 7. Cooling device 70 also includes a supply path 74 that supplies chiller water to cooling heat exchanger 71 from equipment (not shown) that produces chiller water installed outside frozen dessert production apparatus 1, a supply path 75 that supplies chiller water cooled in cooling heat exchanger 71 from cooling heat exchanger 71 to condenser 3, and a discharge path 76 that discharges chiller water from condenser 3 to equipment (not shown) that produces chiller water installed outside frozen dessert production apparatus 1.

[0062] In the frozen dessert production apparatus 1 configured as described above, the refrigerant discharged from the compressor 2 is high-temperature and high-pressure, but by cooling the refrigerant with chiller water in the condenser 3, condensation of the refrigerant and the high pressure that are characteristic of CO2 refrigerants are prevented. The chiller water supplied to the cooling device 70 is cooled with a low-temperature liquid refrigerant that has been decompressed and expanded by the expansion valve 4, thereby further lowering the temperature of the chiller water and increasing the efficiency of heat exchange in the condenser 3. The chiller water whose temperature has been lowered by heat exchange with the chiller water in the cooling device 70 is supplied to the condenser 3 via the supply path 75. Meanwhile, the gaseous refrigerant that has been heated by cooling the chiller water in the cooling heat exchanger 71 merges with the refrigerant heading to the compressor 2 between the accumulator 6 and the heat exchanger 7. The merged refrigerant is completely vaporized in the heat exchanger 7 before flowing into the compressor 2.

[0063] The frozen dessert making apparatus 1 according to this embodiment is provided with the cooling device 70 integrally with the compressor 2 and other components that make up the refrigeration cycle. In other words, the frozen dessert making apparatus 1 also includes the cooling device 70 within a housing that houses the components that make up the refrigeration cycle, such as the compressor 2. If the frozen dessert making apparatus 1 does not include the cooling device 70, a device equivalent to the cooling device 70 would be required, separate from the housing that houses the components that make up the refrigeration cycle, such as the compressor 2. Considering this configuration as a comparative configuration, the frozen dessert making apparatus 1 according to this embodiment is easier to transport and install than the comparative configuration, and does not require the need to secure space to install a device equivalent to the cooling device 70.

[0064] Furthermore, in the frozen dessert production apparatus 1, the refrigerant used to cool the chiller water in the cooling heat exchanger 71 is a refrigerant that has been made high-temperature and high-pressure by the compressor 2 and then made low-temperature and low-pressure by the expansion valve 4. Therefore, the frozen dessert production apparatus 1 has a heat exchanger for pre-cooling the chiller water by the cooling device 70 without imposing a burden on the equipment (not shown) that produces the chiller water. In addition, in the frozen dessert production apparatus 1, the refrigerant compressed by the compressor 2 is used to cool the raw material mix in the evaporator 5, and is also used to cool chiller water in the cooling heat exchanger 71.

[0065] As described above, the frozen dessert making apparatus 1 according to this embodiment includes the agitator 100 as an example of a making section that produces frozen desserts by converting a liquid refrigerant into a gaseous state to cool ingredients, the compressor 2 that compresses the gaseous refrigerant, the condenser 3 that condenses the refrigerant compressed by the compressor 2 using chiller water, and the cooling device 70 that cools the chiller water. This frozen dessert making apparatus 1 can lower the temperature of the water that cools the refrigerant discharged from the compressor 2 without requiring a space for installing a device that cools the chiller water used to cool the refrigerant compressed by the compressor 2 or without imposing the burden of facilities (not shown) for producing the chiller water.

[0066] In the above-described frozen dessert production apparatus 1, the merging path 73 merges the refrigerant discharged from the cooling heat exchanger 71 with the refrigerant heading toward the compressor 2 between the accumulator 6 and the heat exchanger 7, but is not limited to this. The merging path 73 may also merge the refrigerant discharged from the cooling heat exchanger 71 with the refrigerant heading toward the compressor 2 between the heat exchanger 7 and the compressor 2.

[0067] In the above-described embodiment, the hot gas control unit 62 adjusted the frequency of the compressor 2 and the opening degree of the hot gas valve 9 based on the pressure of the gaseous refrigerant evaporated in the evaporator 5 as the state of the evaporator 5, but this is not limited to this. The hot gas control unit 62 may also use the state of the ingredient mix or the frozen dessert cooled by the evaporator 5 as the state of the evaporator 5. Specifically, the hot gas control unit 62 may adjust the opening degree of the hot gas valve 9 based on the temperature of the ingredient mix measured by the ingredient temperature sensor 114, the temperature of the frozen dessert measured by the frozen dessert temperature sensor 115, and the rotational load of the rotating shaft 133 detected by the load sensor 136 as the state of the evaporator 5.

[0068] In addition, in the above-described embodiment, the frozen dessert manufacturing apparatus 1 includes both the mixing device 100 and a refrigeration cycle that cools the raw material mix, etc., being mixed by the mixing device 100, but part of the components of the refrigeration cycle may be provided in a device other than the frozen dessert manufacturing apparatus 1. Furthermore, in the above-described embodiment, the frozen dessert production apparatus 1 has one stirring device 100, but may have, for example, a plurality of stirring devices 100 connected in parallel. In this case, the frozen dessert production apparatus 1 has a plurality of evaporators 5 corresponding to the respective stirring devices 100, and a plurality of hot gas valves 9 that adjust the amount of hot gas flowing into each evaporator 5. The hot gas control unit 62 then individually adjusts the opening degree of each hot gas valve 9 according to the state of each evaporator 5. [Explanation of symbols]

[0069] 1...frozen dessert manufacturing apparatus, 2...compressor, 3...condenser, 4...expansion valve, 5...evaporator, 6...accumulator, 7...heat exchanger, 8...receiver, 9...hot gas valve, 11...separator, 12...return section, 51...refrigerant circuit, 52...branching passage, 60...controller, 61...compressor control section, 62...hot gas control section, 63...expansion valve control section, 70...cooling device, 71...cooling heat exchanger, 72...branching passage, 73...junction passage, 74, 75...supply passage, 76...discharge passage, 100...agitator, 110...cylinder inner tube, 120...cylinder outer tube, 130...agitating section

Claims

1. a production department that produces frozen desserts by cooling ingredients by converting a liquid refrigerant into a gaseous state; a compressor that compresses the gaseous refrigerant; a condenser that condenses the refrigerant compressed by the compressor using chiller water; a cooling device that cools the chiller water; an expansion valve that expands the refrigerant liquefied by the condenser to reduce its pressure; Equipped with the manufacturing unit cools the raw material by covering the cylinder into which the raw material has been poured with the refrigerant whose pressure has been reduced by the expansion valve; The cooling device has a heat exchanger that exchanges heat between the chiller water and the liquid refrigerant, and a branch path that branches off from a flow path extending from the expansion valve toward the production unit and supplies the refrigerant, the pressure of which has been reduced by the expansion valve, to the heat exchanger. Frozen dessert manufacturing equipment.

2. The liquid refrigerant used for heat exchange in the heat exchanger is a refrigerant that has been liquefied in the condenser and then expanded to reduce its pressure. The frozen dessert manufacturing apparatus according to claim 1.

3. The refrigerant after heat exchange in the heat exchanger merges with the refrigerant heading from the manufacturing section to the compressor. The frozen dessert manufacturing apparatus according to claim 1.

4. Carbon dioxide is used as the refrigerant The frozen dessert manufacturing apparatus according to claim 1.

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