Ice-making apparatus and ice-making method

Abstract

The present invention provides an ice-making apparatus that can reduce the refrigeration load of the second refrigeration cycle when a second refrigeration cycle cools a second fluid using a first fluid cooled in a first refrigeration cycle, and then uses the second fluid to produce sherbet ice. [Solution] The ice-making apparatus 100 has the following configuration. The first refrigerator 110 cools the first fluid F1 by a first refrigeration cycle. The second refrigerator 120 cools the second fluid F2, which is colder than the first fluid F1, by a second refrigeration cycle using the first fluid F1 cooled by the first refrigerator 110. The supercooler 130 cools the third fluid F3 to a supercooled state by heat exchange with the second fluid F2. The supercooling release device 160 releases the supercooled state of the third fluid F3 to produce sherbet ice SI. The preheater 140 preheats the third fluid F3 by exchanging heat between the third fluid F3 supplied to the supercooler 130 and the first fluid F1.

Description

[[Technical Field]]

[0001] The present disclosure relates to an ice making device and an ice making method. [[Background Art]]

[0002] Conventionally, inventions relating to a multi-stage refrigeration cycle device including a low-temperature side refrigeration cycle and a high-temperature side refrigeration cycle are known (see, for example, Patent Document 1 below). The multi-stage refrigeration cycle device described in Patent Document 1 is a device for cooling a semiconductor device manufacturing apparatus.

[0003] The multi-stage refrigeration cycle device described in Patent Document 1 includes a first refrigeration cycle in which a first refrigerant that exchanges heat with a cooling medium for cooling a semiconductor device manufacturing apparatus circulates, and a second refrigeration cycle in which a second refrigerant that exchanges heat with the first refrigerant circulates. The multi-stage refrigeration cycle device further includes an intermediate medium circulation line for circulating an intermediate medium between the first refrigeration cycle and the second refrigeration cycle. [[Prior Art Documents]] [[Patent Documents]]

[0004] [[Patent Document 1]] Japanese Unexamined Patent Application Publication No. 2022-174869 [[Summary of the Invention]] [[Problem to be Solved by the Invention]]

[0005] When sherbet ice is produced using a cooling medium cooled in a first refrigeration cycle of a multi-stage refrigeration cycle device such as that disclosed in Patent Document 1 described above, reducing the refrigeration load of the first refrigeration cycle becomes an issue.

[0006] The present disclosure provides an ice making device and an ice making method capable of reducing the refrigeration load of a first refrigeration cycle when a second fluid is cooled in a second refrigeration cycle using a first fluid cooled in the first refrigeration cycle and sherbet ice is produced using the second fluid. [Means for solving the problem]

[0007] Embodiments of the present disclosure provide an ice-making apparatus comprising: a first refrigerator that cools a first fluid by a first refrigeration cycle; a second refrigerator that cools a second fluid at a lower temperature than the first fluid by a second refrigeration cycle utilizing the first fluid cooled by the first refrigerator; a subcooler that cools a third fluid to a supercooled state by heat exchange with the second fluid; a subcooling release device that releases the supercooled state of the third fluid to produce sherbet ice; and a preheater that preheats the third fluid by heat exchange between the third fluid and the first fluid supplied to the subcooler.

[0008] Another embodiment of the present disclosure provides an ice-making method comprising: a first cooling step of cooling a first fluid by a first refrigeration cycle; a second cooling step of cooling a second fluid at a lower temperature than the first fluid by a second refrigeration cycle using the first fluid cooled in the first cooling step; a supercooling step of cooling a third fluid to a supercooled state by heat exchange with the second fluid; a supercooling release step of releasing the supercooled state of the third fluid to produce sherbet ice; and a preheating step of preheating the third fluid and the first fluid by heat exchange before they are cooled in the supercooling step. [Effects of the Invention]

[0009] Each of the above embodiments provides an ice-making apparatus and ice-making method that can reduce the refrigeration load of the first refrigeration cycle when a second fluid is cooled in a second refrigeration cycle using a first fluid cooled in a first refrigeration cycle, and sherbet ice is produced using the second fluid. [Brief explanation of the drawing]

[0010] [Figure 1] This is a circuit diagram showing Embodiment 1 of the ice-making apparatus according to this disclosure. [Figure 2] This flowchart shows an example of an embodiment of the ice-making method described herein. [Figure 3]Figure 1 shows the correlation between the temperature difference between the preheater inlet and outlet of the ice-making machine and the coefficient of performance of the second chiller. [Figure 4] This is a circuit diagram showing Embodiment 2 of the ice-making apparatus according to this disclosure. [Figure 5] This is a circuit diagram showing Embodiment 3 of the ice-making apparatus according to this disclosure. [Figure 6] This is a circuit diagram showing Embodiment 4 of the ice-making apparatus according to this disclosure. [Figure 7] This is a circuit diagram showing Embodiment 5 of the ice-making apparatus according to this disclosure. [Modes for carrying out the invention]

[0011] Hereinafter, embodiments of the ice-making apparatus and ice-making method relating to this disclosure will be described with reference to the attached drawings. In this specification and drawings, substantially identical components may be denoted by the same reference numerals to avoid redundant explanations.

[0012] [Embodiment 1] Figure 1 is a circuit diagram showing Embodiment 1 of the ice-making apparatus according to the present disclosure. The ice-making apparatus 100 of this embodiment is mainly characterized by comprising a first refrigerator 110, a second refrigerator 120, a supercooler 130, a preheater 140, and a supercooling release device 160. The ice-making apparatus 100 may also be equipped with, for example, a filter 150 and an ice storage tank 170.

[0013] The first refrigerator 110 cools the first fluid F1 by a first refrigeration cycle. The second refrigerator 120 cools the second fluid F2, which is colder than the first fluid F1, by a second refrigeration cycle using the first fluid F1 cooled by the first refrigerator 110. The supercooler 130 cools the third fluid F3 to a supercooled state by heat exchange with the second fluid F2. The supercooling release device 160 releases the supercooled state of the third fluid F3 to produce sherbet ice SI. The preheater 140 preheats the third fluid F3 by heat exchange between the third fluid F3 supplied to the supercooler 130 and the first fluid F1. The configuration of each part of the ice-making apparatus 100 according to this embodiment will be described in detail below.

[0014] As described above, the first refrigerator 110 cools the first fluid F1 through the first refrigeration cycle. The first fluid F1 is, for example, a liquid such as water. In the example shown in FIG. 1, the first refrigerator 110 is a vapor compression refrigerator. The first refrigeration cycle of the first refrigerator 110 includes a compressor CM that compresses refrigerant gas, a condenser CA that condenses the compressed refrigerant gas, an expansion valve EX that reduces the pressure of the condensed liquid refrigerant, and an evaporator EV that vaporizes the depressurized liquid refrigerant.

[0015] The first refrigerator 110 allows cooling water CW at approximately 32°C supplied from a cooling tower CT to pass through a coiled internal pipe arranged inside the condenser CA, thereby cooling and condensing the refrigerant gas in the condenser CA. The cooling water CW flows into the internal pipe of the condenser CA via an outgoing cooling water pipe connecting the outlet of the cooling tower CT to the inlet of the internal pipe of the condenser CA in the first refrigerator 110. This outgoing cooling water pipe is provided with a pump P for pressure-feeding the cooling water CW, a valve V for opening and closing the cooling water pipe, and the like.

[0016] The cooling water CW, whose temperature has increased after passing through the internal pipe of the condenser CA of the first refrigerator 110, flows back to the cooling tower CT via a return cooling water pipe connecting the outlet of the internal pipe to the inlet of the cooling tower CT, and is cooled to approximately 32°C in the cooling tower CT. This return cooling water pipe is provided with a valve V for opening and closing the cooling water pipe, and the like. Note that the ice making apparatus 100 may include the cooling tower CT for circulating the cooling water CW to the first refrigerator 110, the cooling water pipe, and the like.

[0017] The first refrigerator 110 allows the first fluid F1 to pass through a coiled internal pipe arranged inside the evaporator EV, thereby cooling the first fluid F1 to a temperature of approximately 7°C by the heat of vaporization of the liquid refrigerant. The outlet of the internal pipe in the evaporator EV of the first refrigerator 110 is connected via a relay pipe provided with a valve V to the inlet of a coiled internal pipe arranged inside the condenser CA of the second refrigerator 120.

[0018] As described above, the second refrigerator 120 is a refrigerator that cools a second fluid F2 having a lower temperature than the first fluid F1 through a second refrigeration cycle using the first fluid F1 cooled by the first refrigerator 110. The second fluid F2 is, for example, brine such as antifreeze. In the example shown in FIG. 1, the second refrigerator 120 is a vapor compression refrigerator similar to the first refrigerator 110.

[0019] The condenser CA of the second refrigerator 120 allows the first fluid F1 of about 7°C cooled by the first refrigerator 110 to pass through an internal pipe disposed therein, and cools and condenses the refrigerant gas through heat exchange with the first fluid F1. In addition, the outlet of the internal pipe of the condenser CA of the second refrigerator 120 is connected to the inlet of the first fluid F1 of the preheater 140 via an outgoing pipe that supplies the first fluid F1 from the second refrigerator 120 to the preheater 140.

[0020] The evaporator EV of the second refrigerator 120 allows the second fluid F2 to pass through a coiled internal pipe disposed therein, and cools the second fluid F2 to a temperature of about -4.5°C by the vaporization heat of the liquid refrigerant present around the internal pipe. In addition, the outlet of the internal pipe of the evaporator EV of the second refrigerator 120 is connected to the refrigerant inlet of the subcooler 130 via an outgoing refrigerant pipe that supplies the second fluid F2 from the second refrigerator 120 to the subcooler 130.

[0021] As described above, the subcooler 130 cools a third fluid F3 to a supercooled state through heat exchange with the second fluid F2. That is, the subcooler 130 is a heat exchanger that causes heat exchange between the second fluid F2 and the third fluid F3. As described above, the second fluid F2 is brine cooled to about -4.5°C. The third fluid F3 is, for example, seawater having a salt content of about 2.5%. Note that the third fluid F3 may be water. The subcooler 130 has a refrigerant inlet and a refrigerant outlet for the second fluid F2, and a fluid inlet and a fluid outlet for the third fluid F3.

[0022] As described above, the refrigerant inlet of the subcooler 130 is connected to the outlet of internal piping located inside the evaporator EV of the second chiller 120, via a supply refrigerant pipe that supplies the second fluid F2 from the second chiller 120 to the subcooler 130. A valve V, a pump P, and a temperature sensor TS are provided in this supply refrigerant pipe for the second fluid F2.

[0023] The refrigerant outlet of the subcooler 130 is connected to the inlet of the internal piping in the evaporator EV of the second chiller 120 via a return refrigerant pipe that recirculates the second fluid F2 from the subcooler 130 to the second chiller 120. A valve V and a temperature sensor TS are provided in this return refrigerant pipe for the second fluid F2.

[0024] The fluid inlet of the supercooler 130 is connected to the fluid outlet of the ice storage tank 170 via a supply pipe SL that supplies a third fluid F3 from the ice storage tank 170 to the supercooler 130. This supply pipe SL is equipped with a valve V, a temperature sensor TS, and a pump P, as well as a preheater 140 and a filter 150. When the pump P is driven, the supply pipe SL supplies the third fluid F3 stored in the ice storage tank 170 to the fluid inlet of the supercooler 130.

[0025] The fluid outlet of the supercooler 130 is connected to the fluid inlet of the ice storage tank 170 via a recirculation pipe RL that recirculates the third fluid F3 from the supercooler 130 to the ice storage tank 170. The recirculation pipe RL recirculates the third fluid F3, which has been cooled to a supercooled state by heat exchange with the second fluid F2 inside the supercooler 130, to the fluid inlet of the ice storage tank 170. In addition to a temperature sensor TS, a supercooling release device 160 is also provided in the recirculation pipe RL.

[0026] As described above, the preheater 140 preheats the third fluid F3 by exchanging heat between the third fluid F3 supplied to the supercooler 130 and the first fluid F1 cooled by the first refrigerator 110. In other words, the preheater 140 is a heat exchanger that exchanges heat between the first fluid F1 and the third fluid F3. As described above, the third fluid F3 is seawater with a salinity of about 2.5% and flows into the preheater 140 at a temperature of about -1.5°C, near its freezing point. The preheater 140 has an inlet and outlet for the first fluid F1 and an inlet and outlet for the third fluid F3.

[0027] The inlet of the first fluid F1 of the preheater 140 is connected to the outlet of the internal piping in the condenser CA of the second chiller 120 via a supply pipe for the first fluid F1 that supplies the first fluid F1 from the second chiller 120 to the preheater 140. The outlet of the first fluid F1 of the preheater 140 is connected to the inlet of the internal piping in the evaporator EV of the first chiller 110 via a return pipe for the first fluid F1 that recirculates the first fluid F1 from the preheater 140 to the first chiller 110. A pump P is provided in this return pipe for the first fluid F1 to pump the first fluid F1 from the preheater 140 to the first chiller 110.

[0028] The inlet of the third fluid F3 of the preheater 140 is connected to the fluid outlet of the ice storage tank 170 via the supply pipe SL, and the outlet of the third fluid F3 of the preheater 140 is connected to the fluid inlet of the subcooler 130 via the supply pipe SL. The preheater 140 exchanges heat between the third fluid F3, which is introduced from the inlet of the third fluid F3 at approximately -1.5°C, and the first fluid F1, which is introduced from the inlet of the first fluid F1 at approximately 12°C.

[0029] The preheater 140 raises the temperature of the third fluid F3 by about 0.5°C through the heat exchange described above, preheating the third fluid F3 to a temperature about 0.5°C higher than its freezing point (about -1.0°C if the third fluid F3 is 2.5% seawater). The preheater 140 also lowers the temperature of the first fluid F1 by about 0.8°C through the heat exchange described above, precooling the first fluid F1 to a temperature of about 11.2°C.

[0030] In this way, preheating the third fluid F3 with the preheater 140 suppresses the formation of fine ice nuclei in the third fluid F3 supplied from the ice storage tank 170 to the supercooler 130, thereby preventing blockage of the supercooler 130 due to freezing of the third fluid F3. Furthermore, precooling the first fluid F1 with the preheater 140 reduces the refrigeration load on the first chiller 110 that cools the first fluid F1.

[0031] As described above, the filter 150 is installed in the supply piping SL that connects the fluid outlet of the ice storage tank 170 and the fluid inlet of the supercooler 130, and is positioned between the preheater 140 and the supercooler 130. The filter 150 removes solid matter such as ice contained in the third fluid F3 and prevents solid matter from flowing into the fluid inlet of the supercooler 130 along with the third fluid F3.

[0032] As described above, the supercooling release unit 160 releases the supercooled state of the third fluid F3, which has been cooled to a supercooled state, in order to produce sherbet ice SI. Specifically, the third fluid F3 is cooled to a supercooled state, which is about 2°C lower than the freezing point (about -3.5°C in the case of 2.5% seawater), by exchanging heat with the second fluid F2 in the supercooler 130. The supercooling release unit 160 releases the supercooled state of the third fluid F3 by applying ultrasonic shock to the supercooled third fluid F3, thereby producing sherbet ice SI.

[0033] The ice storage tank 170 stores the third fluid F3 together with the sherbet ice SI generated by the supercooling releaser 160. The ice storage tank 170 also has an ice outlet for supplying the sherbet ice SI stored inside to the outside. An ice supply pipe equipped with a valve V and a pump P is connected to the ice outlet of the ice storage tank 170. The sherbet ice SI stored inside the ice storage tank 170 is supplied to the outside of the ice storage tank 170 via the ice supply pipe by opening the valve V of the ice supply pipe connected to the ice outlet and driving the pump P, and is used, for example, to maintain the freshness of seafood such as fish.

[0034] Next, an example of an embodiment of the ice-making method according to this disclosure will be described with reference to Figure 2. Figure 2 is a flow chart showing each step of the ice-making method IMM of this embodiment. The ice-making method IMM of this embodiment includes a first cooling step P1, a second cooling step P2, a preheating step P3, a supercooling step P4, and a supercooling release step P5, and can be carried out by the ice-making apparatus 100 shown in Figure 1.

[0035] When the ice-making method IMM of this embodiment, as shown in Figure 2, is started, the ice-making device 100 drives the compressors CM of the first chiller 110 and the second chiller 120. The ice-making device 100 also drives a pump P installed in the supply cooling water piping that supplies cooling water CW from the cooling tower CT to the condenser CA of the first chiller 110. The ice-making device 100 also drives a pump P installed in the return piping that recirculates the first fluid F1 from the preheater 140 to the evaporator EV of the first chiller 110.

[0036] Furthermore, the ice-making device 100 drives a pump P installed in the supply refrigerant piping that supplies the second fluid F2 from the evaporator EV of the second chiller 120 to the subcooler 130. The ice-making device 100 also drives a pump P installed in the supply piping SL that connects the fluid outlet of the ice storage tank 170 to the fluid inlet of the subcooler 130.

[0037] Subsequently, the ice-making device 100 performs a first cooling step P1. In this first cooling step P1, the ice-making device 100 cools the first fluid F1 using the first refrigeration cycle. Specifically, the ice-making device 100 cools the first fluid F1 by passing it through the internal piping of the evaporator EV of the first chiller 110, which constitutes the first refrigeration cycle.

[0038] Next, the ice-making device 100 performs a second cooling step P2. In this second cooling step P2, the ice-making device 100 cools a second fluid F2, which is at a lower temperature than the first fluid F1, using a second refrigeration cycle that utilizes the first fluid F1 cooled in the first cooling step P1. Specifically, the ice-making device 100 passes the first fluid F1, which was cooled in the first refrigerator 110 in the preceding first cooling step P1, through the internal piping of the condenser CA of the second refrigerator 120, which constitutes the second refrigeration cycle, and cools and condenses the refrigerant gas in the condenser CA with the first fluid F1.

[0039] Furthermore, the ice-making device 100 reduces the pressure of the liquid refrigerant condensed in the condenser CA of the second chiller 120 using the expansion valve EX, and supplies it around the internal piping of the evaporator EV of the second chiller 120, which constitutes the second refrigeration cycle. The ice-making device 100 also passes the second fluid F2 through the internal piping of the evaporator EV of the second chiller 120, and cools the second fluid F2, which is at a lower temperature than the first fluid F1, by the heat of vaporization of the liquid refrigerant present around the internal piping.

[0040] Next, the ice-making machine 100 performs a preheating step P3. In this preheating step P3, the ice-making machine 100 preheats the third fluid F3, which will be cooled in the next supercooling step P4, by exchanging heat with the first fluid F1. Specifically, the ice-making machine 100 causes heat exchange between the third fluid F3 and the first fluid F1 in a preheater 140 provided in the supply pipe SL that supplies the third fluid F3 from the ice storage tank 170 to the supercooler 130. As a result, the third fluid F3 is preheated by the first fluid F1, which is at a higher temperature than the third fluid F3, and its temperature rises, while the first fluid F1 is precooled by the third fluid F3, which is at a lower temperature than the first fluid F1, and its temperature decreases.

[0041] Next, the ice-making device 100 performs a supercooling process P4. In this supercooling process P4, the ice-making device 100 cools the third fluid F3 to a supercooled state by heat exchange with the second fluid F2. Specifically, the ice-making device 100 uses a supercooler 130 to exchange heat between the second fluid F2, which was cooled by the second refrigerator 120 in the second cooling process P2, and the third fluid F3, which was preheated in the preheating process P3, thereby cooling the third fluid F3 to a supercooled state below its freezing point.

[0042] Next, the ice-making device 100 performs a supercooling release step P5. In this supercooling release step P5, the ice-making device 100 releases the supercooled state of the third fluid F3 to produce sherbet ice SI. Specifically, the ice-making device 100 releases the supercooled state of the third fluid F3, which was cooled to a supercooled state in the previous supercooling step P4, by applying ultrasonic shock in the supercooling release device 160 to produce sherbet ice SI.

[0043] The sherbet ice SI generated in the supercooling release step P5 flows from the supercooling release unit 160 through the reflux pipe RL along with the third fluid F3 into the ice storage tank 170, where it is stored. This completes the ice-making method IMM of this embodiment shown in Figure 2. Furthermore, the ice-making apparatus 100 can continuously produce sherbet ice SI by repeatedly performing each step of the ice-making method IMM shown in Figure 2.

[0044] The operation of the ice-making apparatus 100 and the ice-making method IMM of this embodiment will be described below.

[0045] As described above, the ice-making apparatus 100 of this embodiment includes a first refrigerator 110, a second refrigerator 120, a supercooler 130, a preheater 140, and a supercooling release device 160. The first refrigerator 110 cools the first fluid F1 by a first refrigeration cycle. The second refrigerator 120 cools the second fluid F2, which is colder than the first fluid F1, by a second refrigeration cycle using the first fluid F1 cooled by the first refrigerator 110. The supercooler 130 cools the third fluid F3 to a supercooled state by heat exchange with the second fluid F2. The supercooling release device 160 releases the supercooled state of the third fluid F3 to produce sherbet ice SI. The preheater 140 preheats the third fluid F3 by heat exchange between the third fluid F3 supplied to the supercooler 130 and the first fluid F1.

[0046] With this configuration, the ice-making apparatus 100 of this embodiment can cool a second fluid F2, which is colder than the first fluid F1, by using the second refrigeration cycle of the second refrigerator 120, which utilizes the first fluid F1 cooled by the first refrigeration cycle of the first refrigerator 110. Furthermore, the ice-making apparatus 100 uses the second fluid F2 cooled by the second refrigerator 120 to produce sherbet ice SI using the supercooler 130 and the supercooling release device 160. At this time, by exchanging heat between the first fluid F1 and the third fluid F3 in the preheater 140, the refrigeration load of the first refrigeration cycle in the first refrigerator 110 can be reduced.

[0047] Here, we consider a comparative example ice maker in which the preheater 140 of the ice maker 100 in Figure 1 is replaced with an electric heater. In this comparative example ice maker, the temperature of the third fluid F3 is raised by 0.5°C above its freezing point by preheating the third fluid F3 with the electric heater. Furthermore, in the comparative example ice maker, the third fluid F3, which is at a temperature 0.5°C higher than its freezing point, is cooled to a supercooled state 2°C below its freezing point by exchanging heat with the second fluid F2 in the supercooler 130. In this case, in the supercooling release unit 160, 2.0°C of the 2.5°C temperature difference of the third fluid F3 before and after cooling by the supercooler 130 contributes to ice making. Also, (0.5°C / 2.5°C) × 100 = 20% of the refrigeration capacity of the supercooler 130 is lost.

[0048] In contrast, in the ice-making apparatus 100 of this embodiment, if the capacity of the subcooler 130 is Q [kW], then the capacity of the preheater 140 is (1 / 5) × Q. Also, if the coefficient of performance of the second refrigerator 120 that cools the second fluid F2 to -4.5°C is COP, then the capacity of the condenser CA of the second refrigerator 120 is {(COP+1) / COP} × Q.

[0049] Here, in the ice-making apparatus 100 of this embodiment, if the inlet temperature of the first fluid F1 passing through the internal piping of the condenser CA of the second refrigerator 120 is 7°C and the outlet temperature is 12°C, then the temperature difference between the inlet temperature and the outlet temperature of the first fluid F1 with respect to the condenser CA of the second refrigerator 120 is 5°C. Under these conditions, if the temperature difference between the temperature of the first fluid F1 flowing into the preheater 140 and the temperature of the first fluid F1 flowing out of the preheater 140 is ΔT [°C], then the following equations (1) and (2) hold.

[0050] 5.0 ∝ {(COP+1) / COP} × Q or Cp×ρ×U×5.0={(COP+1) / COP}×Q (1)

[0051] ΔT∝(1 / 5)×Q or Cp × ρ × U × ΔT = (1 / 5) × Q ... (2)

[0052] In equations (1) and (2) above, Cp is the specific heat [kJ / kg°C] and ρ is the density [kg / m³]. 3 ] and U is the flow rate [m 3 The value is [ / s]. Here, if COP is 4, then ΔT is 0.8℃, and as shown in Figure 1, the first fluid F1 at 7℃ cooled in the evaporator EV of the first refrigerator 110 is heated to 12℃ in the condenser CA of the second refrigerator 120. Furthermore, the first fluid F1 heated to 12℃ is cooled to 11.2℃ in the preheater 140 and recirculated to the evaporator EV of the first refrigerator 110. As a result, in the ice-making apparatus 100 of this embodiment, the refrigeration load of the first refrigeration cycle by the first refrigerator 110 is reduced to {(11.2℃-7℃) / (12℃-7℃)}×100=84%.

[0053] Figure 3 is a graph showing the relationship between the temperature difference ΔT of the first fluid F1 at the inlet and outlet of the preheater 140 and the coefficient of performance COP of the second chiller 120. As shown in Figure 3, the higher the coefficient of performance COP of the second chiller 120, the larger the temperature difference ΔT between the first fluid F1 flowing into the preheater 140 and the first fluid F1 flowing out of the preheater 140 can be. As a result, the effect of reducing the refrigeration load in the first chiller 110 can be increased.

[0054] Furthermore, by using a preheater 140, the ice-making apparatus 100 of this embodiment does not require an electric heater like the ice-making apparatus of the comparative example, thereby reducing power consumption. Therefore, according to this embodiment, a highly efficient supercooling type sherbet ice SI ice-making apparatus 100 can be provided.

[0055] Furthermore, the ice-making apparatus 100 of this embodiment further includes an ice storage tank 170 that stores the third fluid F3 together with the sherbet ice SI produced in the supercooling releaser 160. The preheater 140 is provided in the supply pipe SL that supplies the third fluid F3 from the ice storage tank 170 to the supercooler 130, and the supercooling releaser 160 is provided in the recirculation pipe RL that recirculates the third fluid F3 from the supercooler 130 to the ice storage tank 170.

[0056] With this configuration, the ice-making device 100 can preheat the third fluid F3, which is seawater or water stored in the ice storage tank 170 and is at a temperature near its freezing point, by exchanging heat with the first fluid F1 in the preheater 140 when supplying it to the supercooler 130 via the supply pipe SL. Furthermore, when the ice-making device 100 returns the third fluid F3, which has been cooled to a supercooled state by heat exchange with the second fluid F2 in the supercooler 130, to the ice storage tank 170 via the return pipe RL, the supercooling state can be released by the supercooling release device 160 provided in the return pipe RL.

[0057] Therefore, the ice-making device 100 can transfer the sherbet ice SI produced in the supercooling release unit 160 to the ice storage tank 170 along with the third fluid F3 and store it in the ice storage tank 170. Furthermore, the ice-making device 100 can circulate the third fluid F3 between the ice storage tank 170 and the supercooler 130, and while reducing the refrigeration load of the first refrigerator 110 with the preheater 140, it can continuously produce sherbet ice SI with the supercooler 130 and the supercooling release unit 160.

[0058] Furthermore, in the ice-making apparatus 100 of this embodiment, the first refrigerator 110 and the second refrigerator 120 are vapor compression type refrigerators.

[0059] This configuration allows the ice-making device 100 to achieve higher cooling efficiency for both the first chiller 110 and the second chiller 120 compared to a case where at least one of the first chiller 110 and the second chiller 120 is an absorption chiller. Furthermore, compared to absorption chillers, the vapor compression type second chiller 120 and the second chiller 120 can be started up in a short time, deterioration over time can be suppressed, and they can be easily miniaturized or enlarged.

[0060] Furthermore, the ice-making method IMM of this embodiment includes, as described above, a first cooling step P1, a second cooling step P2, a preheating step P3, a supercooling step P4, and a supercooling release step P5. The first cooling step P1 is a step of cooling the first fluid F1 by a first refrigeration cycle. The second cooling step P2 is a step of cooling the second fluid F2, which is at a lower temperature than the first fluid F1, by a second refrigeration cycle that utilizes the first fluid F1 cooled in the first cooling step P1. The supercooling step P4 is a step of cooling the third fluid F3 to a supercooled state by heat exchange with the second fluid F2. The supercooling release step P5 is a step of releasing the supercooled state of the third fluid F3 to produce sherbet ice SI. The preheating step P3 is a step of preheating the third fluid F3, which is cooled in the supercooling step P4, by heat exchange with the first fluid F1.

[0061] With this configuration, the IMM ice-making method of this embodiment can use the first fluid F1 cooled in the first cooling step P1 to cool the second fluid F2, which is at a lower temperature than the first fluid F1, in the second cooling step P2. Furthermore, in the preheating step P3, the IMM ice-making method of this embodiment can pre-cool the first fluid F1 by heat exchange between the third fluid F3 and the first fluid F1, and then cool the pre-cooled first fluid F1 with the first refrigerator 110. As a result, the cooling load of the first refrigeration cycle that cools the first fluid F1 in the first cooling step P1 can be reduced.

[0062] As described above, the ice-making apparatus 100 and ice-making method IMM of this embodiment cool a second fluid F2 in a second refrigeration cycle using a first fluid F1 cooled in a first refrigeration cycle, and produce sherbet ice SI using the second fluid F2. In this embodiment, it is possible to provide an ice-making apparatus 100 and ice-making method IMM that can reduce the refrigeration load of the first refrigeration cycle.

[0063] [Embodiment 2] Next, with reference to Figure 4, Embodiment 2 of the ice-making apparatus and ice-making method according to this disclosure will be described. Figure 4 is a circuit diagram showing the ice-making apparatus 100A of this embodiment.

[0064] The ice-making apparatus 100A of this embodiment differs from the ice-making apparatus 100 of Embodiment 1 described above in that the first chiller 110A and the second chiller 120A are absorption chillers. The other components of the ice-making apparatus 100A according to this embodiment are the same as those of the ice-making apparatus 100 of Embodiment 1 described above, so the same reference numerals are used for the same parts and their description is omitted.

[0065] The first chiller 110A is equipped with an evaporator EV', an absorber AB, a regenerator RG, and a condenser CA', and cools the first fluid F1 by circulating water as a refrigerant and an aqueous lithium bromide (LiBr) solution as a working refrigerant.

[0066] The evaporator EV' of the first chiller 110A has a coiled internal piping through which the first fluid F1 passes. The evaporator EV' cools the first fluid F1 passing through the internal piping by evaporating the refrigerant present around the internal piping under vacuum conditions. The first fluid F1 cooled by the evaporator EV' is a liquid such as water, and is cooled to a temperature of about 7°C as it passes through the internal piping of the evaporator EV'.

[0067] The absorber AB of the first chiller 110A absorbs the refrigerant vapor generated by the heat of the first fluid F1 in the evaporator EV' into the working refrigerant. The absorber AB cools the working refrigerant that has been heated and regenerated in the regenerator RG by passing cooling water CW through the coiled internal piping located inside it.

[0068] The regenerator RG of the first chiller 110A regenerates the working refrigerant by heating the working refrigerant, which has absorbed refrigerant vapor in the absorber AB, thereby desorbing the absorbed refrigerant. The regenerator RG heats the working refrigerant by passing a thermal fluid WHF, such as hot water heated by waste heat or unused heat, through a coil-shaped internal piping located inside it. The waste heat or unused heat used to heat the thermal fluid WHF can be, for example, waste heat from a waste incineration plant, unused heat from a factory, or geothermal energy. The thermal fluid WHF flows into the piping inside the regenerator RG after being heated to a temperature of approximately 85°C by the waste heat or unused heat.

[0069] The condenser CA' of the first chiller 110A condenses the refrigerant vapor that has been desorbed from the working refrigerant in the regenerator RG, returning it to liquid refrigerant, and circulates this refrigerant to the evaporator EV'. The condenser CA' cools and condenses the refrigerant vapor by passing cooling water CW through a coiled internal pipe located inside it. The cooling water CW is supplied from the cooling tower CT to the first chiller 110A via a cooling water pipe connecting the cooling tower CT and the first chiller 110A, and via a pump P installed in the middle of the cooling water pipe.

[0070] The second refrigerator 120A is a refrigerator that cools a second fluid F2, which is colder than the first fluid F1, by a second refrigeration cycle that utilizes the first fluid F1 cooled by the first refrigeration cycle of the first refrigerator 110A.

[0071] The second refrigerator 120A, like the first refrigerator 110A, is equipped with an evaporator EV', an absorber AB, a regenerator RG, and a condenser CA', and circulates a refrigerant and a working refrigerant to cool the second fluid F2. In the second refrigerator 120A, the refrigerant is a mixture of water and 1-propanol, and the working refrigerant is a mixture of LiBr, water, and 1-propanol. The second fluid F2 is, for example, a brine such as antifreeze, and is cooled to a temperature of about -4°C to -5°C by the second refrigerator 120A.

[0072] The evaporator EV' of the second refrigerator 120A cools the second fluid F2 by passing it through a coiled internal pipe located inside it. The absorber AB of the second refrigerator 120A cools the working refrigerant by passing the first fluid F1, which has been cooled by the first refrigerator 110, through a coiled internal pipe located inside it.

[0073] Furthermore, the regenerator RG of the second chiller 120A heats the working refrigerant by passing a thermal fluid WHF, such as hot water heated by waste heat or unused heat, through a coiled internal pipe located inside it. Also, the condenser CA' of the second chiller 120A cools and condenses the refrigerant vapor that has been released from the working refrigerant by passing the first fluid F1, cooled by the first chiller 110, through a coiled internal pipe located inside it.

[0074] As described above, in the ice-making apparatus 100A of this embodiment, the first refrigerator 110A and the second refrigerator 120A are absorption-type refrigerators.

[0075] With this configuration, the ice-making apparatus 100 of this embodiment can use water or a mixture of water as a refrigerant, thereby reducing refrigerant costs and environmental impact compared to the case where at least one of the first refrigerator 110A and the second refrigerator 120A is a vapor compression type refrigerator. Furthermore, the first refrigerator 110A and the second refrigerator 120 can be driven using the thermal fluid WHF generated from waste heat or unused heat, thereby reducing the energy consumption of the ice-making apparatus 100A. In addition, the ice-making apparatus 100A of this embodiment can implement the ice-making method IMM shown in Figure 2, similar to the ice-making apparatus 100 of Embodiment 1 described above.

[0076] Furthermore, the ice-making apparatus 100A and ice-making method IMM of this embodiment, similar to Embodiment 1, cools a second fluid F2 in a second refrigeration cycle using a first fluid F1 cooled in a first refrigeration cycle, and produces sherbet ice SI using the second fluid F2. In this case, the ice-making apparatus 100A and ice-making method IMM of this embodiment can also reduce the refrigeration load of the first refrigeration cycle, similar to Embodiment 1 described above.

[0077] [Embodiment 3] Next, with reference to Figure 5, Embodiment 3 of the ice-making apparatus according to this disclosure will be described. Figure 5 is a circuit diagram showing the ice-making apparatus 100B of this embodiment.

[0078] The ice-making apparatus 100B of this embodiment differs from the ice-making apparatuses 100 and 100A of embodiments 1 and 2 described above in that the first chiller 110A is an absorption chiller and the second chiller 120 is a vapor compression chiller. The other components of the ice-making apparatus 100B according to this embodiment are the same as those of the ice-making apparatuses 100 and 100A of embodiments 1 and 2 described above, so the same reference numerals are used for the same parts and their description is omitted.

[0079] The ice-making apparatus 100B of this embodiment can enjoy the same benefits as the ice-making apparatus 100A of Embodiment 2 described above, as well as the benefits of the first refrigerator 110A being an absorption-type refrigerator. Furthermore, the ice-making apparatus 100B of this embodiment can enjoy the same benefits as the ice-making apparatus 100 of Embodiment 1 described above, as well as the benefits of the second refrigerator 120 being a vapor compression-type refrigerator. In addition, the ice-making apparatus 100B of this embodiment can implement the ice-making method IMM shown in Figure 2, similar to the ice-making apparatus 100 of Embodiment 1 described above.

[0080] Furthermore, the ice-making apparatus 100B and ice-making method IMM of this embodiment, similar to Embodiment 1 described above, cools a second fluid F2 in a second refrigeration cycle using a first fluid F1 cooled in a first refrigeration cycle, and produces sherbet ice SI using the second fluid F2. In this case, the ice-making apparatus 100B and ice-making method IMM of this embodiment can also reduce the refrigeration load of the first refrigeration cycle, similar to Embodiment 1 described above.

[0081] [Embodiment 4] Next, with reference to Figure 6, Embodiment 4 of the ice-making apparatus according to this disclosure will be described. Figure 6 is a circuit diagram showing the ice-making apparatus 100C of this embodiment.

[0082] The ice-making apparatus 100C of this embodiment differs from the ice-making apparatus 100 of Embodiment 1 described above in that it further comprises a diversion header DH and a confluence header IH. The diversion header DH diverts the first fluid F1 cooled by the first chiller 110 to its respective supply destinations, such as the second chiller 120 and the first equipment E1. The confluence header IH combines the first fluid F1 used by the second chiller 120 with the f1 that has undergone heat exchange with the third fluid F3 in the preheater 140 and returns it to the first chiller 110.

[0083] The other components of the ice-making device 100C according to this embodiment are the same as those of the ice-making device 100 according to Embodiment 1 described above, so the same parts are denoted by the same reference numerals and their description is omitted.

[0084] The diversion header DH and the confluence header IH include, for example, a straight main pipe and a plurality of branch pipes branching off from the main pipe. In the diversion header DH, each branch pipe that diverts the first fluid F1 from the main pipe to its respective supply destination is provided with a valve V. In the confluence header IH, each branch pipe that returns the first fluid F1 from its respective supply destination to the main pipe is also provided with a valve V.

[0085] One branch pipe of the diversion header DH is connected to the inlet of the internal piping in the condenser CA of the second chiller 120 via a supply pipe that supplies the first fluid F1 from the diversion header DH to the second chiller 120. One branch pipe of the confluence header IH is connected to the outlet of the internal piping in the condenser CA of the second chiller 120 via a return pipe that recirculates the first fluid F1 from the second chiller 120 to the confluence header IH.

[0086] Furthermore, another branch pipe of the diversion header DH is connected to the inlet of the first fluid F1 in the preheater 140 via a supply pipe that supplies the first fluid F1 from the diversion header DH to the preheater 140. Additionally, another branch pipe of the confluence header IH is connected to the outlet of the first fluid F1 in the preheater 140 via a return pipe that recirculates the first fluid F1 from the preheater 140 back to the confluence header IH.

[0087] Furthermore, another branch pipe of the diversion header DH may be connected to the inlet of the first fluid F1 of the first equipment E1, such as an air conditioning unit, via a supply pipe that supplies the first fluid F1 from the diversion header DH to the first equipment E1. Similarly, another branch pipe of the confluence header IH may be connected to the outlet of the first fluid F1 of the first equipment E1, via a return pipe that recirculates the first fluid F1 from the first equipment E1 to the confluence header IH.

[0088] According to the ice-making apparatus 100C of this embodiment, the first fluid F1 cooled in the first chiller 110 can be diverted by the flow divider header DH and supplied to other equipment such as the first equipment E1 other than the second chiller 120 and preheater 140 for use. Furthermore, the first fluid F1 used in the second chiller 120, preheater 140 and other equipment can be merged by the confluence header IH and returned to the first chiller 110. Note that the other equipment may include one or more pieces of equipment other than the first equipment E1.

[0089] Furthermore, the ice-making apparatus 100C and ice-making method IMM of this embodiment, similar to Embodiment 1, cools a second fluid F2 in a second refrigeration cycle using a first fluid F1 cooled in a first refrigeration cycle, and produces sherbet ice SI using the second fluid F2. In this case, the ice-making apparatus 100C and ice-making method IMM of this embodiment can also reduce the refrigeration load of the first refrigeration cycle, similar to Embodiment 1.

[0090] In this embodiment of the ice-making apparatus 100C, the first refrigerator 110 and the second refrigerator 120 are vapor compression type refrigerators. However, the first refrigerator 110 may be an absorption type first refrigerator 110A. Similarly, the second refrigerator 120 may be an absorption type second refrigerator 120A.

[0091] [Embodiment 5] Finally, with reference to Figure 7, Embodiment 5 of the ice-making apparatus according to this disclosure will be described. Figure 7 is a circuit diagram showing the ice-making apparatus 100D of this embodiment.

[0092] In the ice-making apparatus 100D of this embodiment, the preheater 140 exchanges heat between the first fluid F1 and the third fluid F3, which have been cooled by the first refrigerator 110 and are not yet used by the second refrigerator 120. The second refrigerator 120 cools the second fluid F2 by a second refrigeration cycle that utilizes the first fluid F1, which has exchanged heat with the third fluid F3 in the preheater 140.

[0093] Specifically, in the ice-making machine 100D, the outlet of the internal piping in the evaporator EV of the first chiller 110 is connected to the inlet of the first fluid F1 of the preheater 140 via a supply pipe that supplies the first fluid F1 from the first chiller 110 to the preheater 140. Also, in the ice-making machine 100D, the outlet of the first fluid F1 of the preheater 140 is connected to the inlet of the internal piping in the condenser CA of the second chiller 120 via a relay pipe that supplies the first fluid F1 from the preheater 140 to the second chiller 120.

[0094] Furthermore, in the ice-making machine 100D, the outlet of the internal piping in the condenser CA of the second chiller 120 is connected to the inlet of the internal piping in the evaporator EV of the first chiller 110 via a return pipe that recirculates the first fluid F1 from the second chiller 120 to the first chiller 110. A pump P for pressurizing the first fluid F1 is provided in this return pipe for the first fluid F1.

[0095] The ice-making apparatus 100D and ice-making method IMM of this embodiment, similar to Embodiment 1, cools a second fluid F2 in a second refrigeration cycle using a first fluid F1 cooled in a first refrigeration cycle, and produces sherbet ice SI using the second fluid F2. In this case, the ice-making apparatus 100D and ice-making method IMM of this embodiment can also reduce the refrigeration load of the first refrigeration cycle, similar to Embodiment 1.

[0096] In this embodiment of the ice-making apparatus 100D, the first refrigerator 110 and the second refrigerator 120 are vapor compression type refrigerators. However, the first refrigerator 110 may be an absorption type first refrigerator 110A. Similarly, the second refrigerator 120 may be an absorption type second refrigerator 120A.

[0097] Preferred embodiments of the present disclosure have been described above. However, the present disclosure is not limited to the embodiments described above. Various modifications, substitutions, etc., can be applied to the embodiments described above without departing from the scope of the present disclosure. Furthermore, each of the features described with reference to the embodiments described above may be combined as appropriate, as long as they do not conflict technically. [Explanation of Symbols]

[0098] 100 Ice makers 100A Ice Maker 100B Ice Maker 100C Ice Maker 100D Ice Maker 110 No. 1 Refrigeration Unit 110A 1st refrigerator 120 Second Refrigeration Unit 120A Second Refrigeration Unit 130 Supercooler 140 Preheater 160 Supercooling release device 170 Ice storage tanks DH flow diverter header F1 1st fluid F2 2nd fluid F3 3rd fluid IH Junction Header IMM Ice Making Method P1 1st cooling process P2 2nd cooling process P3 Preheating process P4 Supercooling process P5 Supercooling release process SI Sherbet Ice SL supply piping

Claims

1. A first refrigerator that cools the first fluid by a first refrigeration cycle, A second refrigerator cools a second fluid, which is at a lower temperature than the first fluid, by a second refrigeration cycle using the first fluid cooled by the first refrigerator, A supercooler that cools the third fluid to a supercooled state by heat exchange with the second fluid, A supercooling release device that releases the supercooled state of the third fluid to produce sherbet ice, The system includes a preheater that preheats the third fluid by exchanging heat between the third fluid and the first fluid supplied to the subcooler. Ice making machine.

2. A flow splitter that splits the first fluid cooled by the first refrigerator to the second refrigerator and the preheater, The system further includes a confluence header that combines the first fluid used in the second refrigerator with the first fluid that has undergone heat exchange with the third fluid in the preheater, and returns the combined fluid to the first refrigerator. The ice-making apparatus according to claim 1.

3. The preheater exchanges heat between the first fluid and the third fluid before they are cooled by the first refrigerator and used by the second refrigerator. The second refrigerator cools the second fluid by a second refrigeration cycle that utilizes the first fluid which has exchanged heat with the third fluid in the preheater. The ice-making apparatus according to claim 1.

4. The system further comprises an ice storage tank for storing the third fluid together with the sherbet ice generated by the supercooling release device, The preheater is provided in the supply piping that supplies the third fluid from the ice storage tank to the supercooler. The supercooling release device is provided in the recirculation piping that recirculates the third fluid from the supercooler to the ice storage tank. The ice-making apparatus according to claim 1.

5. The first and second refrigerators are vapor compression type refrigerators. The ice-making apparatus according to claim 1.

6. The first and second refrigerators are absorption-type refrigerators. The ice-making apparatus according to claim 1.

7. The first refrigerator is an absorption type refrigerator, The second refrigerator is a vapor compression type refrigerator. The ice-making apparatus according to claim 1.

8. A first cooling step in which a first fluid is cooled by a first refrigeration cycle, A second cooling step in which a second fluid, which is at a lower temperature than the first fluid, is cooled by a second refrigeration cycle using the first fluid cooled in the first cooling step, A supercooling step in which the third fluid is cooled to a supercooled state by heat exchange with the second fluid, A supercooling release step is performed to release the supercooled state of the third fluid and generate sherbet ice, The process includes a preheating step in which the third fluid and the first fluid are preheated by exchanging heat before they are cooled in the supercooling step, Ice-making methods.

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