WO2022138520A1 - Operation control method and cooling system - Google Patents

Operation control method and cooling system Download PDF

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Publication number
WO2022138520A1
WO2022138520A1 PCT/JP2021/046894 JP2021046894W WO2022138520A1 WO 2022138520 A1 WO2022138520 A1 WO 2022138520A1 JP 2021046894 W JP2021046894 W JP 2021046894W WO 2022138520 A1 WO2022138520 A1 WO 2022138520A1
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WIPO (PCT)
Prior art keywords
refrigerant
liquid refrigerant
liquid
temperature
cooler
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PCT/JP2021/046894
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French (fr)
Japanese (ja)
Inventor
行介 山田
弥彦 芳野
伊朗 井筒
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株式会社Boban
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Publication of WO2022138520A1 publication Critical patent/WO2022138520A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B1/00—Compression machines, plants or systems with non-reversible cycle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25C—PRODUCING, WORKING OR HANDLING ICE
    • F25C1/00—Producing ice

Definitions

  • the present invention relates to an operation control method and a cooling system.
  • a full-liquid ice maker described in Patent Document 1 is known as a cooling system for producing an ice slurry.
  • salt water is circulated in an ice maker filled with a liquid refrigerant, and the salt water is cooled by heat exchange between the liquid refrigerant and the salt water to generate an ice slurry.
  • An object of the present invention is to provide an operation control method and a cooling system capable of controlling the temperature of a liquid refrigerant and exhibiting stable cooling characteristics.
  • An operation control method for a cooling system having a cooler that cools a medium to be cooled by exchanging heat with a liquid refrigerant comprising controlling the temperature of the liquid refrigerant in the cooler by supplying a high-pressure gaseous gas refrigerant to the liquid refrigerant.
  • the gas refrigerant is generated by compressing the refrigerant with a compressor.
  • a compressor that compresses the refrigerant into a high-pressure gaseous gas refrigerant
  • a condenser that condenses the gas refrigerant into a high-pressure liquid liquid refrigerant
  • a cooler that cools the medium to be cooled by heat exchange with the liquid refrigerant
  • a cooling system comprising: a control device for controlling the temperature of the liquid refrigerant in the cooler by supplying the gas refrigerant to the liquid refrigerant.
  • the temperature of the liquid refrigerant in the cooler is stable, and stable cooling characteristics can be exhibited.
  • the temperature of the liquid refrigerant can be controlled with excellent responsiveness.
  • FIG. 1 is a diagram showing an overall configuration diagram of a cooling system according to the first embodiment.
  • FIG. 2 is a cross-sectional view showing a cooler and a liquid level measuring instrument.
  • FIG. 3 is a block diagram showing a control method of the control device.
  • FIG. 4 is a block diagram showing a control method of the control device.
  • FIG. 5 is a cross-sectional view showing a cooler and a liquid level measuring instrument included in the cooling system according to the second embodiment.
  • the upper side of the paper surface in FIGS. 2 and 5 is the upper side in the vertical direction
  • the lower side of the paper surface is the lower side in the vertical direction.
  • the cooling system 1 shown in FIG. 1 is a system that continuously produces an ice slurry S using salt water B (brine) as a raw material.
  • the ice slurry S refers to sherbet-like ice in which fine ice is turbid in salt water, and may also be referred to as slurry ice, ice slurry, slurry ice, or the like.
  • the cooling system 1 includes a compressor 21, a condenser 22, a cooler 23 (evaporator), and a liquid level measuring unit 24. Further, the cooling system 1 includes a pipe 251 connecting the compressor 21 and the condenser 22, a pipe 252 connecting the condenser 22 and the cooler 23, and a pipe 253 connecting the cooler 23 and the compressor 21. And a pipe 254 that bypasses the pipe 251 and the pipe 252 without passing through the condenser 22. Further, the cooling system 1 has a liquid level adjusting valve 26 provided in the middle of the pipe 252 and a pressure adjusting valve 27 provided in the middle of the pipe 254. Each of these elements constitutes a refrigerant circuit 2 in which the refrigerant R circulates.
  • the refrigerant R is compressed by driving the compressor 21 to form a high-temperature high-pressure gas.
  • the refrigerant R (hereinafter, also referred to as “gas refrigerant Rg”) that has become a high-temperature and high-pressure gas in the compressor 21 flows into the condenser 22 through the pipe 251 and is condensed by heat exchange with air by the operation of the blower fan 221. ⁇ It liquefies and becomes a high-pressure liquid.
  • the high-pressure liquid refrigerant R (hereinafter also referred to as “liquid refrigerant Rl”) in the condenser 22 flows into the cooler 23 through the pipe 252 and evaporates by heat exchange with the salt water B in the cooler 23.
  • the amount of the liquid refrigerant Rl flowing into the cooler 23 is adjusted by the liquid level adjusting valve 26. Further, a part of the gas refrigerant Rg (hot gas) turned into a high-temperature and high-pressure gas by the compressor 21 is supplied to the liquid refrigerant Rl flowing in the pipe 252 through the pipe 254 connected to the pipe 251.
  • the pressure (temperature) of the liquid refrigerant Rl flowing into the cooler 23 can be controlled.
  • the amount of the high gas refrigerant Rg supplied to the liquid refrigerant Rl is adjusted by the pressure adjusting valve 27.
  • the refrigerant R which has become a low-pressure gas due to heat exchange with the salt water B in the cooler 23, is returned to the compressor 21 via the pipe 253, compressed by the compressor 21, and discharged as the gas refrigerant Rg again. Will be done.
  • the refrigerant circuit 2 continuously cools the salt water B in the cooler 23 by circulating the refrigerant R in such a heat exchange cycle.
  • the amount of the liquid refrigerant Rl supplied to the cooler 23 is adjusted by the liquid level adjusting valve 26, and the amount of the liquid refrigerant Rl in the cooler 23, that is, the liquid level height Da of the liquid refrigerant Rl is adjusted.
  • the target liquid level height Dt which is the control target, is maintained.
  • the pressure (temperature) of the liquid refrigerant Rl supplied to the cooler 23 is adjusted by the pressure adjusting valve 27, and the pressure (temperature) of the liquid refrigerant Rl in the cooler 23 is the control target pressure Pt (target temperature). It is kept at Tt).
  • the amount and pressure (temperature) of the liquid refrigerant Rl in the cooler 23 can be maintained at the target values in this way. Therefore, heat exchange between the refrigerant R and the salt water B can be stably performed under desired conditions. Therefore, the salt water B can be continuously cooled stably under appropriate conditions, and the ice slurry S can be efficiently produced. In addition, the ice slurry S produced becomes more homogeneous, and high-quality ice slurry S can be produced.
  • the cooling system 1 includes a storage tank 31 for storing the salt water B and the ice slurry S generated from the salt water B, a pump 32 for circulating the salt water B, and the salt water B supplied to the cooler 23. It has a concentration sensor 33 for detecting a salt concentration, and a concentration sensor 33. Further, the cooling system 1 has a pipe 341 connecting the storage tank 31 and the cooler 23, and a pipe 342 connecting the cooler 23 and the storage tank 31, and a pump 32 is installed in the middle of the pipe 341. The concentration sensor 33 is installed in the cooler 23. Each of these elements constitutes a salt water circulation path 3 (cooled medium circulation path) through which salt water circulates. However, the location of the concentration sensor 33 is not particularly limited as long as it can detect the salt concentration of the salt water B supplied to the cooler 23.
  • the storage tank 31 is provided with a stirring blade 311 for stirring the salt water B and the ice slurry S in the tank, and a motor 312 for rotating the stirring blade 311. This makes it possible to suppress the aggregation of the ice slurry S in the storage tank 31. Further, the storage tank 31 is provided with a discharge pipe 313 for discharging the ice slurry S stored in the tank.
  • the salt water B in the storage tank 31 is supplied to the cooler 23 through the pipe 341 by driving the pump 32.
  • the salt water B supplied into the cooler 23 is cooled by heat exchange with the liquid refrigerant Rl in the cooler 23.
  • the salt water B cooled by the cooler 23 is returned to the storage tank 31 through the pipe 342, and is supplied to the cooler 23 again through the pipe 341.
  • the ice slurry S generated by cooling is stored in the storage tank 31.
  • the salt water circulation path 3 continuously produces the ice slurry S by repeating such a salt water circulation cycle.
  • the cooling system 1 has a control device 4 that controls the drive of each part of the cooling system 1.
  • the control device 4 includes, for example, a processor composed of a computer and processing information, and a memory communicably connected to the processor. Various programs necessary for operating the cooling system 1 are stored in the memory. The processor reads and executes various programs and the like stored in the memory. As a result, the operation of the cooling system 1 as described below is realized.
  • the cooler 23 includes a main evaporator 231, a sub-evaporator 235, and a pressure sensor 239 that detects the pressure of the liquid refrigerant Rl in the main evaporator 231.
  • the pipe 252 is connected to the lower end of the main evaporator 231 and the pipe 253 is connected to the upper end of the sub-evaporator 235.
  • the liquid refrigerant Rl which has become a high-pressure liquid in the condenser 22, is supplied to the main evaporator 231 through the pipe 252.
  • the low-pressure gaseous refrigerant R evaporated and vaporized by heat exchange with the salt water B in the main evaporator 231 is returned from the sub-evaporator 235 to the compressor 21 through the pipe 253.
  • the main evaporator 231 has an outer pipe 232 and an inner pipe 233 coaxially arranged inside the outer pipe 232.
  • the outer pipe 232 and the inner pipe 233 are circular pipes whose ends are closed, respectively.
  • the outer pipe 232 and the inner pipe 233 are not limited to circular pipes, respectively.
  • the outer pipe 232 and the inner pipe 233 are installed upright, and the shaft faces in the vertical direction. That is, the main evaporator 231 is a vertical double-tube evaporator.
  • the main evaporator 231 is a full-liquid evaporator, and almost the entire space between the outer pipe 232 and the inner pipe 233 is filled with the liquid refrigerant Rl.
  • the space will also be referred to as "refrigerant storage unit 234".
  • the salt water B flows in the inner pipe 233. Therefore, heat exchange between the salt water B and the liquid refrigerant Rl is performed through the wall surface of the inner pipe 233.
  • the inner pipe 233 may be made of a material having excellent mechanical strength and high thermal conductivity, such as iron, copper, aluminum, titanium, and stainless steel. preferable. Further, in order to increase the heat exchange efficiency between the liquid refrigerant Rl and the salt water B, the inner pipe 233 is preferably as thin as possible as long as the mechanical strength can be maintained.
  • the sub-evaporator 235 is installed side by side with the main evaporator 231 in the horizontal direction.
  • the sub-evaporator 235 is a circular tube with both ends closed. Further, the sub-evaporator 235 is installed upright, and its axis faces in the vertical direction.
  • Such a sub-evaporator 235 is connected to the refrigerant storage unit 234 via a pair of pipes 236. Therefore, the liquid refrigerant Rl supplied to the refrigerant storage unit 234 is also supplied to the sub-evaporator 235 through these pipes 236.
  • the pressures (internal pressures) of the sub-evaporator 235 and the refrigerant storage unit 234 are equal to each other, and the liquid level height of the liquid refrigerant Rl in the sub-evaporator 235 is the same as the liquid level height of the liquid refrigerant Rl in the refrigerant storage unit 234. equal.
  • the lower end of the sub-evaporator 235 is located above the lower end of the main evaporator 231 in the vertical direction. Therefore, for example, the amount of the liquid refrigerant Rl in the sub-evaporator 235 is higher than the case where the lower end is at the same height as the lower end of the main evaporator 231 or the lower end is located below the lower end of the main evaporator 231 in the vertical direction. Can be reduced. As a result, the amount of the refrigerant R used can be reduced.
  • the sub-evaporator 235 is vertically longer than the main evaporator 231 and its upper end is located vertically above the upper end of the main evaporator 231. Therefore, a space 237 located above the liquid refrigerant Rl is formed in the sub-evaporator 235. As will be described later, a dehumidifying member 238 is arranged in the space 237.
  • the refrigerant R evaporated and vaporized by heat exchange with the salt water B in the main evaporator 231 is returned to the compressor 21 from the upper end of the sub-evaporator 235 through the pipe 253.
  • the compressor 21 may fail due to a sudden increase in the cylinder internal pressure due to the liquid compression. Therefore, a dehumidifying member 238 for removing the liquid (humidity) contained in the vaporized refrigerant R is arranged in the space 237 of the sub-evaporator 235.
  • the dehumidifying member 238 has an umbrella shape with a large number of through holes formed.
  • the through hole serves as a passage for the refrigerant R.
  • the vaporized refrigerant R comes into contact with the dehumidifying member 238 while rising from the liquid surface toward the pipe 253, and the liquid (humidity) contained in the refrigerant R is removed by the contact, and the drier refrigerant R is compressed. It is returned to the machine 21. This makes it possible to prevent the compressor 21 from failing as described above.
  • a plurality of dehumidifying members 238 are arranged in the vertical direction to improve the dehumidifying effect.
  • the dehumidifying member 238 may be omitted when the refrigerant R is almost completely evaporated by heat exchange with the salt water B and the sufficiently dry gaseous refrigerant R returns to the compressor 21. Further, for example, when the dehumidifying member 238 is insufficiently dried, a superheater is arranged in the middle of the pipe 253 in place of or in addition to the dehumidifying member 238, and the refrigerant R is heated by the superheater before the compressor. It may be configured to return to 21.
  • the liquid level measuring unit 24 includes a refrigerant storage pipe 241 and a liquid level detection sensor 242.
  • the refrigerant storage pipe 241 is installed side by side with the sub-evaporator 235 in the horizontal direction. Further, the refrigerant storage pipe 241 is installed upright, and its axis faces in the vertical direction. Further, the refrigerant storage pipe 241 is connected to the sub-evaporator 235 via a pair of pipes 243. Therefore, the liquid refrigerant Rl supplied to the refrigerant storage unit 234 is also supplied to the refrigerant storage pipe 241 via the sub-evaporator 235.
  • the pressures (internal pressures) in the refrigerant storage pipe 241 and the sub-evaporator 235 and the refrigerant storage unit 234 are equal to each other. Therefore, as shown by the chain line in FIG. 2, the liquid level heights of the liquid refrigerants Rl in the refrigerant storage pipe 241 and the sub-evaporator 235 and the refrigerant storage unit 234 are equal to each other. Therefore, by detecting the liquid level height of the liquid refrigerant Rl in the refrigerant storage pipe 241, it is possible to detect the liquid level height of the liquid refrigerant Rl in the refrigerant storage unit 234.
  • a liquid level detection sensor 242 is installed in the refrigerant storage pipe 241, and the liquid level of the liquid refrigerant Rl in the refrigerant storage pipe 241 is detected by the liquid level detection sensor 242, whereby the liquid refrigerant in the refrigerant storage unit 234 is detected. It is configured to detect the liquid level height of Rl.
  • the liquid level detection sensor 242 By installing the liquid level detection sensor 242 at a location different from the refrigerant storage unit 234 in this way, the liquid of the liquid refrigerant Rl in the refrigerant storage unit 234 is not hindered from heat exchange between the liquid refrigerant Rl and the salt water B.
  • the surface height can be detected.
  • the configuration of the liquid level measuring unit 24 is not particularly limited as long as the liquid level height of the liquid refrigerant Rl in the refrigerant storage unit 234 can be detected.
  • the refrigerant storage pipe 241 is a circular pipe with both ends closed, and its length and diameter are smaller than those of the sub-evaporator 235. By making the refrigerant storage pipe 241 smaller than the sub-evaporator 235 in this way, the amount of the liquid refrigerant Rl in the refrigerant storage pipe 241 can be reduced. As a result, the amount of the refrigerant R used can be reduced.
  • the liquid level adjusting valve 26 is a valve for controlling the supply amount of the liquid refrigerant Rl to the main evaporator 231 and is installed on the upstream side of the main evaporator 231.
  • the liquid level adjusting valve 26 can be adjusted not only on / off but also in multiple steps or steplessly with an opening degree of 0 to 100%.
  • the drive of the liquid level adjusting valve 26 is controlled by the control device 4.
  • the control device 4 determines the liquid level height Da of the liquid refrigerant Rl in the refrigerant storage unit 234 indicated by the output of the liquid level detection sensor 242, the target liquid level height Dt which is the control target, and the target liquid level height Dt. Perform feedback control to match.
  • the liquid level height Da of the liquid refrigerant Rl in the refrigerant storage unit 234 can be maintained at the target liquid level height Dt (difference from the target liquid level height Dt can be suppressed), and the liquid refrigerant can be suppressed.
  • the heat exchange between Rl and the salt water B can be stably performed under desired conditions. Therefore, the ice slurry S can be stably and efficiently produced. In addition, the ice slurry S produced becomes more homogeneous, and high-quality ice slurry S can be produced.
  • the control device 4 controls the drive of the liquid level adjusting valve 26 by analog control, particularly PID control. Specifically, the control device 4 controls the PID for the liquid level height Da by using the deviation De between the liquid level height Da and the target liquid level Dt, the integral of the deviation De, and the derivative of the deviation De. Run. Note that FIG. 3 shows the proportional gain Kpp, the integrated gain Kpi, and the differential gain Kpd. According to the PID control, the fluctuation of the liquid level height Da of the liquid refrigerant Rl is reduced and the liquid level height Da is stabilized as compared with the simple ON / OFF control. Therefore, heat exchange between the liquid refrigerant Rl and the salt water B can be performed more stably under desired conditions.
  • the ice slurry S can be stably and efficiently produced.
  • the ice slurry S produced becomes more homogeneous, and high-quality ice slurry S can be produced.
  • the control method of the liquid level adjusting valve 26 is not particularly limited, and may be, for example, other analog control such as P control or PI control, or may be digital control.
  • the pressure adjusting valve 27 is a valve for controlling the pressure of the liquid refrigerant Rl in the main evaporator 231 and is installed on the upstream side of the main evaporator 231.
  • the pressure adjusting valve 27 By supplying the high-temperature high-pressure gaseous gas refrigerant Rg to the high-pressure liquid liquid refrigerant Rl, the pressure of the liquid refrigerant Rl flowing into the refrigerant storage unit 234 can be increased, and the supply amount of the gas refrigerant Rg can be increased by the pressure adjusting valve 27.
  • the pressure of the liquid refrigerant Rl in the refrigerant storage unit 234 can be controlled. According to such a control method, the pressure of the liquid refrigerant Rl in the refrigerant storage unit 234 can be controlled with a simple configuration.
  • Such a pressure adjusting valve 27 can be adjusted not only on / off but also in multiple steps or steplessly with an opening degree of 0 to 100%.
  • the drive of the pressure adjusting valve 27 is controlled by the control device 4.
  • the control device 4 executes feedback control for matching the pressure Pa of the liquid refrigerant Rl in the refrigerant storage unit 234 indicated by the output of the pressure sensor 239 with the target pressure Pt, which is the control target. ..
  • the temperature of the liquid refrigerant Rl is proportional to its pressure. Therefore, controlling the pressure of the liquid refrigerant Rl is synonymous with controlling the temperature of the liquid refrigerant Rl. Therefore, by executing such feedback control, the temperature Ta of the liquid refrigerant Rl in the refrigerant storage unit 234 can be maintained at the target temperature Tt (difference from the target temperature Tt can be suppressed), and the liquid can be suppressed.
  • the heat exchange between the refrigerant Rl and the salt water B can be stably performed under desired conditions. Therefore, the ice slurry S can be stably and efficiently produced. In addition, the ice slurry S produced becomes more homogeneous, and high-quality ice slurry S can be produced.
  • the target temperature Tt temperature Ta of the liquid refrigerant Rl
  • the freezing point Tf freezing point
  • Tf-10 ° C. ⁇ Tt ⁇ Tf is preferable, Tf-10 ° C. ⁇ Tt ⁇ Tf-3 ° C. is more preferable, and Tf-10 ° C. ⁇ Tt ⁇ Tf-5 ° C. is more preferable. Is even more preferable.
  • the temperature of the liquid refrigerant Rl so as to satisfy the relationship of Tf-10 ° C. ⁇ Ta ⁇ Tf, and the liquid refrigerant Rl so as to satisfy the relationship of Tf-8 ° C. ⁇ Ta ⁇ Tf-3 ° C. It is more preferable to control the temperature of the liquid refrigerant Rl, and it is further preferable to control the temperature of the liquid refrigerant Rl so as to satisfy the relationship of Tf-7 ° C ⁇ Ta ⁇ Tf-5 ° C.
  • the cooling system 1 uses a full-liquid main evaporator 231 with high work efficiency, a high work amount can be secured even if the temperature difference ⁇ T is small, and the salt water B is cooled at a sufficient speed. It becomes possible to do. That is, the operation with a small temperature difference ⁇ T is realized because the full-liquid main evaporator 231 is used. Further, according to the cooling system 1, since the temperature of the liquid refrigerant Rl can be closely controlled, the temperature difference ⁇ T can be controlled accurately.
  • the control device 4 Since the freezing point Tf of the salt water B is determined by the salt concentration, the freezing point Tf of the salt water B can be obtained if the salt concentration of the salt water B is known. Therefore, the control device 4 first obtains the freezing point Tf of the salt water B from the salt concentration of the salt water B in the cooler 23 indicated by the output of the concentration sensor 33. Next, the control device 4 sets the target temperature Tt of the liquid refrigerant Rl so that the temperature difference ⁇ T becomes a predetermined value. Next, the control device 4 obtains the pressure of the liquid refrigerant Rl corresponding to the set target temperature Tt, and sets this as the target pressure Pt.
  • the control device 4 controls the drive of the pressure adjusting valve 27 by analog control, particularly PID control. Specifically, as shown in FIG. 4, the control device 4 executes PID control for the pressure Pa by using the deviation Pe between the pressure Pa and the target pressure Pt, the integral of the deviation Pe, and the derivative of the deviation Pe. ..
  • FIG. 4 shows the proportional gain Kpp, the integrated gain Kpi, and the differential gain Kpd. According to the PID control, the fluctuation of the pressure Pa of the refrigerant R is reduced and the pressure Pa is stabilized as compared with the simple ON / OFF control. Therefore, heat exchange between the liquid refrigerant Rl and the salt water B can be performed more stably under desired conditions.
  • the ice slurry S can be stably and efficiently produced.
  • the ice slurry S produced becomes more homogeneous, and high-quality ice slurry S can be produced.
  • the control method of the pressure adjusting valve 27 is not particularly limited, and may be, for example, other analog control such as P control or PI control, or may be digital control.
  • the control device 4 has a plurality of pressure control modes in order to efficiently cool the salt water B while suppressing freezing of the salt water B (adhesion of ice to the inner pipe 233) in the cooler 23. ..
  • a quenching mode M1 and a slow cooling mode M2 are provided as a plurality of pressure control modes.
  • the slow cooling mode M2 is the control mode described above, and is a mode in which the drive of the pressure adjusting valve 27 is controlled so that Tf ⁇ 10 ° C. ⁇ Ta ⁇ Tf.
  • the quenching mode M1 is a mode in which the temperature Ta is lower than that of the slow cooling mode M2, and the drive of the pressure adjusting valve 27 is controlled so as to have a larger temperature difference ⁇ T. Therefore, the quenching mode M1 has a larger work load of the liquid refrigerant Rl than the slow cooling mode M2, and the cooling capacity of the salt water B is higher.
  • the control device 4 sets the temperature above the freezing point Tf as the threshold value SH, controls the drive of the pressure adjusting valve 27 in the quenching mode M1 when the temperature of the salt water B is above the threshold value SH, and slow-cools mode when the temperature of the salt water B is less than the threshold value SH.
  • the drive of the pressure adjusting valve 27 is controlled by M2.
  • the salt water B can be cooled with the largest possible temperature difference (the temperature difference just before freezing) while suppressing the freezing of the salt water B. Therefore, the salt water B can be cooled in a shorter time while suppressing the adhesion of ice into the inner pipe 233. Therefore, the production efficiency of the ice slurry S is improved.
  • the threshold value SH is not particularly limited and varies depending on the performance of each part, but for example, the temperature is preferably 0 ° C. to 7 ° C. higher than the freezing point Tf and 3 ° C. to 5 ° C. higher than the freezing point Tf. Is more preferable.
  • the salt water B can be cooled to a lower temperature in the quenching mode M1 while suppressing the freezing of the salt water B, so that the salt water B can be cooled in a shorter time and the production efficiency of the ice slurry S is improved.
  • the control device 4 may have a drive mode other than the quenching mode M1 and the slow cooling mode M2. Further, the control device 4 may have only the slow cooling mode M2.
  • the cooling system 1 has been described above.
  • a cooling system 1 for example, an ice slurry S made from seawater can be continuously generated. Therefore, the cooling system 1 can be installed in, for example, a fishing boat or a fishing port, and the ice slurry S generated by the cooling system 1 can be used for keeping fresh fish cold.
  • the storage tank 31 may be replenished with fresh seawater in an amount commensurate with the amount of ice slurry S consumed for keeping the fresh fish cold by a replenishment pump (not shown). According to the ice slurry S, it is possible to keep the fresh fish cold for a long time without damaging it.
  • the cooling system 1 of the present embodiment has a stirring device 5 for stirring the salt water B in the cooler 23, in addition to the configuration of the first embodiment described above.
  • the stirring device 5 has a rotating shaft 51 arranged along the central axis of the inner pipe 233, a motor 52 for rotating the rotating shaft 51, and a plurality of blades 53 fixed to the rotating shaft 51. Further, the tip of each blade 53 is in contact with the inner peripheral surface of the inner pipe 233.
  • the rotation shaft 51 is rotated, the blades 53 rotate, and spiral convection occurs in the salt water B flowing in the inner pipe 233. Therefore, the heat exchange efficiency between the liquid refrigerant Rl and the salt water B is increased, and the salt water B can be cooled more efficiently.
  • the ice can be scraped off by the blade 53. Therefore, the growth of ice on the inner peripheral surface of the inner tube 233 can be suppressed, and the decrease in the production efficiency of the ice slurry S can be suppressed.
  • each blade 53 may be non-contact with the inner peripheral surface of the inner pipe 233.
  • the dimensional accuracy of the inner pipe 233 and the blade 53 is not required, so that the device configuration becomes simpler.
  • the present invention is not limited thereto.
  • the configuration of each part can be replaced with an arbitrary configuration that exhibits the same function, or an arbitrary configuration can be added.
  • the salt water B is used as the cooling medium, but the cooling medium is not limited to this.
  • the cooling medium may be various aqueous solutions such as various drinking waters and calcium chloride aqueous solutions.
  • the cooling system 1 is not limited to the application for producing the ice slurry S, and for example, liquids, particularly water, soft drinks, milk, fruit juices, vegetable juices, alcoholic drinks and other various drinking waters are unfrozen. It may be used for cooling as it is. That is, the cooling system 1 may be used as a cooling system. Further, the cooling system 1 may be used as a chiller (cooling water circulation device) for cooling a target device or sample.
  • the operation control method of the cooling system 1 having the cooler 23 for cooling the salt water B as the cooling medium by heat exchange with the liquid refrigerant R1 supplies the liquid refrigerant Rl with the high-pressure gaseous gas refrigerant Rg.
  • the temperature of the liquid refrigerant R1 in the cooler 21 is controlled. Therefore, the temperature Ta of the liquid refrigerant Rl in the refrigerant storage unit 234 can be maintained at the target temperature Tt (difference from the target temperature Tt can be suppressed), and heat exchange between the liquid refrigerant Rl and the salt water B is desired. It can be performed stably under the conditions of. Thereby, the ice slurry S can be stably and efficiently produced. In addition, the ice slurry S produced becomes more homogeneous, and high-quality ice slurry S can be produced. Therefore, its industrial applicability is great.
  • Cooling system 2 ... Refrigerator circuit, 21 ... Compressor, 22 ... Condenser, 221 ... Blower fan, 23 ... Cooler, 231 ... Main evaporator, 232 ... Outer pipe, 233 ... Inner pipe, 234 ... Refrigerator storage Department, 235 ... Sub-evaporator, 236 ... Piping, 237 ... Space, 238 ... Dehumidifying member, 239 ... Pressure sensor, 24 ... Liquid level measuring unit, 241 ... Refrigerator storage pipe, 242 ... Liquid level detection sensor, 243 ... Piping, 251 ... Piping, 252 ... Piping, 253 ... Piping, 254 ... Piping, 26 ...

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Devices That Are Associated With Refrigeration Equipment (AREA)
  • Production, Working, Storing, Or Distribution Of Ice (AREA)

Abstract

The present invention controls liquid-refrigerant temperature, whereby stabilized cooling properties can be demonstrated.　In this method of controlling the operation of a refrigerating system 1 having a chiller 23 that chills saltwater B by heat exchange with a liquid refrigerant Rℓ, the liquid refrigerant Rℓ is supplied with a gas refrigerant Rg in a high-pressure gaseous state to control the temperature of the liquid refrigerant Rℓ inside the chiller 23. Furthermore, a refrigerant R is compressed with a compressor 21 to generate the gas refrigerant Rg, and the gas refrigerant Rg is condensed with a condenser 22 to generate the liquid refrigerant Rℓ. Furthermore, on the basis of the pressure of the liquid refrigerant Rℓ inside the chiller 23, the quantity of the gas refrigerant Rg supplied to the liquid refrigerant Rℓ is feedback-controlled.

Description

運転制御方法および冷却システムOperation control method and cooling system
　本発明は、運転制御方法および冷却システムに関する。 The present invention relates to an operation control method and a cooling system.
　例えば、氷スラリーを製造する冷却システムとして特許文献１に記載された満液式の製氷機が知られている。特許文献１の製氷機では、液冷媒で満たされた製氷機に塩水を循環させ、液冷媒と塩水との熱交換により塩水を冷却して氷スラリーを生成する。 For example, a full-liquid ice maker described in Patent Document 1 is known as a cooling system for producing an ice slurry. In the ice maker of Patent Document 1, salt water is circulated in an ice maker filled with a liquid refrigerant, and the salt water is cooled by heat exchange between the liquid refrigerant and the salt water to generate an ice slurry.
特開２０２０－１０６２１２号公報Japanese Unexamined Patent Publication No. 2020-106212
　しかしながら、このような特許文献１の製氷機では液冷媒の温度を制御しないため、冷媒の温度が安定せず、安定した冷却特性を発揮することができない。 However, in such an ice maker of Patent Document 1, since the temperature of the liquid refrigerant is not controlled, the temperature of the refrigerant is not stable and stable cooling characteristics cannot be exhibited.
　本発明の目的は、液冷媒の温度を制御し、安定した冷却特性を発揮することができる運転制御方法および冷却システムを提供することにある。 An object of the present invention is to provide an operation control method and a cooling system capable of controlling the temperature of a liquid refrigerant and exhibiting stable cooling characteristics.
　このような目的は、下記の本発明により達成される。 Such an object is achieved by the following invention.
　（１）　液冷媒との熱交換により被冷却媒体を冷却する冷却機を有する冷却システムの運転制御方法であって、
　前記液冷媒に高圧ガス状のガス冷媒を供給することにより、前記冷却機内での前記液冷媒の温度を制御することを特徴とする運転制御方法。 (1) An operation control method for a cooling system having a cooler that cools a medium to be cooled by exchanging heat with a liquid refrigerant.
An operation control method comprising controlling the temperature of the liquid refrigerant in the cooler by supplying a high-pressure gaseous gas refrigerant to the liquid refrigerant.
　（２）　冷媒を圧縮機で圧縮することにより前記ガス冷媒を生成し、
　前記ガス冷媒を凝縮器で凝縮することにより前記液冷媒を生成する上記（１）に記載の運転制御方法。 (2) The gas refrigerant is generated by compressing the refrigerant with a compressor.
The operation control method according to (1) above, wherein the liquid refrigerant is generated by condensing the gas refrigerant with a condenser.
　（３）　前記冷却機内の前記液冷媒の圧力に基づいて前記液冷媒に供給する前記ガス冷媒の量をフィードバック制御する上記（１）または（２）に記載の運転制御方法。 (3) The operation control method according to (1) or (2) above, wherein the amount of the gas refrigerant supplied to the liquid refrigerant is feedback-controlled based on the pressure of the liquid refrigerant in the cooler.
　（４）　前記液冷媒に供給する前記ガス冷媒の量をＰＩＤ制御により制御する上記（３）に記載の運転制御方法。 (4) The operation control method according to (3) above, wherein the amount of the gas refrigerant supplied to the liquid refrigerant is controlled by PID control.
　（５）　前記液冷媒の温度をＴａ（℃）とし、前記被冷却媒体の凝固点をＴｆ（℃）としたとき、
　Ｔｆ－１０℃≦Ｔａ≦Ｔｆの関係を満足するように前記液冷媒の温度を制御する上記（１）から（４）のいずれか１項に記載の運転制御方法。 (5) When the temperature of the liquid refrigerant is Ta (° C) and the freezing point of the medium to be cooled is Tf (° C).
The operation control method according to any one of (1) to (4) above, wherein the temperature of the liquid refrigerant is controlled so as to satisfy the relationship of Tf-10 ° C. ≤ Ta ≤ Tf.
　（６）　Ｔｆ－１０℃≦Ｔａ≦Ｔｆの関係を満足するように前記液冷媒の温度を制御する徐冷モードと、前記徐冷モードよりもＴａが低くなるように前記液冷媒の温度を制御する急冷モードと、を有し、
　前記被冷却媒体の温度が閾値以上のときは前記急冷モードで前記液冷媒の温度を制御し、
　前記被冷却媒体の温度が前記閾値未満のときは前記徐冷モードで前記液冷媒の温度を制御する上記（５）に記載の運転制御方法。 (6) A slow cooling mode in which the temperature of the liquid refrigerant is controlled so as to satisfy the relationship of Tf-10 ° C. ≤ Ta ≤ Tf, and a slow cooling mode in which the temperature of the liquid refrigerant is controlled so that Ta is lower than the slow cooling mode. Has a quenching mode, and has
When the temperature of the medium to be cooled is equal to or higher than the threshold value, the temperature of the liquid refrigerant is controlled in the quenching mode.
The operation control method according to (5) above, wherein when the temperature of the medium to be cooled is less than the threshold value, the temperature of the liquid refrigerant is controlled in the slow cooling mode.
　（７）　前記冷却機内の前記液冷媒の量が制御目標となるように、前記冷却機内に供給される前記液冷媒の量を制御する上記（１）から（６）のいずれかに記載の運転制御方法。 (7) The operation according to any one of (1) to (6) above, which controls the amount of the liquid refrigerant supplied into the cooler so that the amount of the liquid refrigerant in the cooler becomes the control target. Control method.
　（８）　前記冷却機内の前記液冷媒の量に基づいて前記冷却機に供給する前記液冷媒の量をフィードバック制御する上記（７）に記載の運転制御方法。 (8) The operation control method according to (7) above, wherein the amount of the liquid refrigerant supplied to the cooler is feedback-controlled based on the amount of the liquid refrigerant in the cooler.
　（９）　前記冷却機に供給する前記液冷媒の量をＰＩＤ制御により制御する上記（８）に記載の運転制御方法。 (9) The operation control method according to (8) above, wherein the amount of the liquid refrigerant supplied to the cooler is controlled by PID control.
　（１０）　冷媒を圧縮して高圧ガス状のガス冷媒とする圧縮機と、
　前記ガス冷媒を凝縮して高圧液状の液冷媒とする凝縮器と、
　前記液冷媒との熱交換により被冷却媒体を冷却する冷却機と、
　前記液冷媒に前記ガス冷媒を供給することにより、前記冷却機内における前記液冷媒の温度を制御する制御装置と、を有することを特徴とする冷却システム。 (10) A compressor that compresses the refrigerant into a high-pressure gaseous gas refrigerant,
A condenser that condenses the gas refrigerant into a high-pressure liquid liquid refrigerant,
A cooler that cools the medium to be cooled by heat exchange with the liquid refrigerant, and
A cooling system comprising: a control device for controlling the temperature of the liquid refrigerant in the cooler by supplying the gas refrigerant to the liquid refrigerant.
　本発明の運転制御方法および冷却システムによれば、液冷媒の温度を制御するため、冷却機内での冷媒の温度が安定し、安定した冷却特性を発揮することができる。特に、液冷媒に高圧ガス状のガス冷媒を供給することにより優れた応答性で液冷媒の温度を制御することができる。 According to the operation control method and the cooling system of the present invention, since the temperature of the liquid refrigerant is controlled, the temperature of the refrigerant in the cooler is stable, and stable cooling characteristics can be exhibited. In particular, by supplying a high-pressure gaseous gas refrigerant to the liquid refrigerant, the temperature of the liquid refrigerant can be controlled with excellent responsiveness.
図１は、第１実施形態に係る冷却システムの全体構成図を示す図である。FIG. 1 is a diagram showing an overall configuration diagram of a cooling system according to the first embodiment. 図２は、冷却機および液面計測器を示す断面図である。FIG. 2 is a cross-sectional view showing a cooler and a liquid level measuring instrument. 図３は、制御装置の制御方法を示すブロック図である。FIG. 3 is a block diagram showing a control method of the control device. 図４は、制御装置の制御方法を示すブロック図である。FIG. 4 is a block diagram showing a control method of the control device. 図５は、第２実施形態に係る冷却システムが有する冷却機および液面計測器を示す断面図である。FIG. 5 is a cross-sectional view showing a cooler and a liquid level measuring instrument included in the cooling system according to the second embodiment.
　以下、本発明の運転制御方法および冷却システムを添付図面に示す実施形態に基づいて詳細に説明する。なお、図２および図５中の紙面上側が鉛直方向上側であり、紙面下側が鉛直方向下側である。 Hereinafter, the operation control method and the cooling system of the present invention will be described in detail based on the embodiments shown in the attached drawings. The upper side of the paper surface in FIGS. 2 and 5 is the upper side in the vertical direction, and the lower side of the paper surface is the lower side in the vertical direction.
　図１に示す冷却システム１は、塩水Ｂ（ブライン）を原料として氷スラリーＳを連続的に生成するシステムである。氷スラリーＳとは、塩水中に微細な氷が混濁したシャーベット状の氷のことをいい、スラリー氷、アイススラリー、スラリーアイス等とも呼ばれる場合がある。 The cooling system 1 shown in FIG. 1 is a system that continuously produces an ice slurry S using salt water B (brine) as a raw material. The ice slurry S refers to sherbet-like ice in which fine ice is turbid in salt water, and may also be referred to as slurry ice, ice slurry, slurry ice, or the like.
　冷却システム１は、圧縮機２１と、凝縮器２２と、冷却機２３（蒸発器）と、液面計測部２４と、を有する。また、冷却システム１は、圧縮機２１と凝縮器２２とを接続する配管２５１と、凝縮器２２と冷却機２３とを接続する配管２５２と、冷却機２３と圧縮機２１とを接続する配管２５３と、凝縮器２２を経由せずに配管２５１と配管２５２とをバイパスする配管２５４と、を有する。また、冷却システム１は、配管２５２の途中に設けられた液面調整バルブ２６と、配管２５４の途中に設けられた圧力調整バルブ２７と、を有する。これら各要素により、冷媒Ｒが循環する冷媒回路２が構成される。 The cooling system 1 includes a compressor 21, a condenser 22, a cooler 23 (evaporator), and a liquid level measuring unit 24. Further, the cooling system 1 includes a pipe 251 connecting the compressor 21 and the condenser 22, a pipe 252 connecting the condenser 22 and the cooler 23, and a pipe 253 connecting the cooler 23 and the compressor 21. And a pipe 254 that bypasses the pipe 251 and the pipe 252 without passing through the condenser 22. Further, the cooling system 1 has a liquid level adjusting valve 26 provided in the middle of the pipe 252 and a pressure adjusting valve 27 provided in the middle of the pipe 254. Each of these elements constitutes a refrigerant circuit 2 in which the refrigerant R circulates.
　このような冷媒回路２では、圧縮機２１の駆動により冷媒Ｒが圧縮されて高温高圧ガス状となる。圧縮機２１で高温高圧ガス状となった冷媒Ｒ（以下「ガス冷媒Ｒｇ」とも言う）は、配管２５１を通って凝縮器２２に流入し、送風ファン２２１の作動による空気との熱交換により凝縮・液化して高圧液状となる。凝縮器２２で高圧液状となった冷媒Ｒ（以下「液冷媒Ｒｌ」とも言う）は、配管２５２を通って冷却機２３に流入し、冷却機２３内での塩水Ｂとの熱交換により蒸発・気化して低圧ガス状となる。なお、冷却機２３に流入する液冷媒Ｒｌの量は、液面調整バルブ２６により調整される。また、圧縮機２１で高温高圧ガス状となったガス冷媒Ｒｇ（ホットガス）の一部は、配管２５１に接続された配管２５４を通って配管２５２内を流れる液冷媒Ｒｌに供給される。ガス冷媒Ｒｇを液冷媒Ｒｌに供給することにより、冷却機２３に流入する液冷媒Ｒｌの圧力（温度）を制御することができる。液冷媒Ｒｌに供給する高ガス冷媒Ｒｇの量は、圧力調整バルブ２７により調整される。冷却機２３内での塩水Ｂとの熱交換によって低圧ガス状となった冷媒Ｒは、配管２５３を介して圧縮機２１に戻され、圧縮機２１により圧縮されて再びガス冷媒Ｒｇとなって吐出される。冷媒回路２は、このような熱交換サイクルで冷媒Ｒを循環させることにより、冷却機２３において塩水Ｂを連続的に冷却する。 In such a refrigerant circuit 2, the refrigerant R is compressed by driving the compressor 21 to form a high-temperature high-pressure gas. The refrigerant R (hereinafter, also referred to as “gas refrigerant Rg”) that has become a high-temperature and high-pressure gas in the compressor 21 flows into the condenser 22 through the pipe 251 and is condensed by heat exchange with air by the operation of the blower fan 221.・ It liquefies and becomes a high-pressure liquid. The high-pressure liquid refrigerant R (hereinafter also referred to as “liquid refrigerant Rl”) in the condenser 22 flows into the cooler 23 through the pipe 252 and evaporates by heat exchange with the salt water B in the cooler 23. It evaporates into a low-pressure gas. The amount of the liquid refrigerant Rl flowing into the cooler 23 is adjusted by the liquid level adjusting valve 26. Further, a part of the gas refrigerant Rg (hot gas) turned into a high-temperature and high-pressure gas by the compressor 21 is supplied to the liquid refrigerant Rl flowing in the pipe 252 through the pipe 254 connected to the pipe 251. By supplying the gas refrigerant Rg to the liquid refrigerant Rl, the pressure (temperature) of the liquid refrigerant Rl flowing into the cooler 23 can be controlled. The amount of the high gas refrigerant Rg supplied to the liquid refrigerant Rl is adjusted by the pressure adjusting valve 27. The refrigerant R, which has become a low-pressure gas due to heat exchange with the salt water B in the cooler 23, is returned to the compressor 21 via the pipe 253, compressed by the compressor 21, and discharged as the gas refrigerant Rg again. Will be done. The refrigerant circuit 2 continuously cools the salt water B in the cooler 23 by circulating the refrigerant R in such a heat exchange cycle.
　冷却システム１の運転中は、液面調整バルブ２６によって冷却機２３へ供給する液冷媒Ｒｌの量が調整され、冷却機２３内の液冷媒Ｒｌの量すなわち液冷媒Ｒｌの液面高さＤａが制御目標である目標液面高さＤｔに保たれる。さらに、圧力調整バルブ２７によって冷却機２３へ供給される液冷媒Ｒｌの圧力（温度）が調整され、冷却機２３内の液冷媒Ｒｌの圧力（温度）が制御目標である目標圧力Ｐｔ（目標温度Ｔｔ）に保たれる。このように、冷却機２３内の液冷媒Ｒｌの量および圧力（温度）を目標値に維持することにより、冷媒Ｒと塩水Ｂとの熱交換を所望の条件で安定して行うことができる。そのため、適当な条件で安定して塩水Ｂを連続冷却することができ、氷スラリーＳを効率的に生成することができる。また、生成される氷スラリーＳがより均質なものとなり、高品質な氷スラリーＳを生成することができる。 During the operation of the cooling system 1, the amount of the liquid refrigerant Rl supplied to the cooler 23 is adjusted by the liquid level adjusting valve 26, and the amount of the liquid refrigerant Rl in the cooler 23, that is, the liquid level height Da of the liquid refrigerant Rl is adjusted. The target liquid level height Dt, which is the control target, is maintained. Further, the pressure (temperature) of the liquid refrigerant Rl supplied to the cooler 23 is adjusted by the pressure adjusting valve 27, and the pressure (temperature) of the liquid refrigerant Rl in the cooler 23 is the control target pressure Pt (target temperature). It is kept at Tt). By maintaining the amount and pressure (temperature) of the liquid refrigerant Rl in the cooler 23 at the target values in this way, heat exchange between the refrigerant R and the salt water B can be stably performed under desired conditions. Therefore, the salt water B can be continuously cooled stably under appropriate conditions, and the ice slurry S can be efficiently produced. In addition, the ice slurry S produced becomes more homogeneous, and high-quality ice slurry S can be produced.
　また、冷却システム１は、塩水Ｂおよび塩水Ｂから生成された氷スラリーＳを貯留するための貯留タンク３１と、塩水Ｂを循環させるためのポンプ３２と、冷却機２３に供給される塩水Ｂの塩分濃度を検出する濃度センサー３３と、を有する。また、冷却システム１は、貯留タンク３１と冷却機２３とを接続する配管３４１と、冷却機２３と貯留タンク３１とを接続する配管３４２と、を有し、配管３４１の途中にポンプ３２が設置され、冷却機２３内に濃度センサー３３が設置されている。これら各要素により、塩水が循環する塩水循環路３（被冷却媒体循環路）が構成される。ただし、濃度センサー３３の配置場所は、冷却機２３に供給される塩水Ｂの塩分濃度を検出することができれば、特に限定されない。 Further, the cooling system 1 includes a storage tank 31 for storing the salt water B and the ice slurry S generated from the salt water B, a pump 32 for circulating the salt water B, and the salt water B supplied to the cooler 23. It has a concentration sensor 33 for detecting a salt concentration, and a concentration sensor 33. Further, the cooling system 1 has a pipe 341 connecting the storage tank 31 and the cooler 23, and a pipe 342 connecting the cooler 23 and the storage tank 31, and a pump 32 is installed in the middle of the pipe 341. The concentration sensor 33 is installed in the cooler 23. Each of these elements constitutes a salt water circulation path 3 (cooled medium circulation path) through which salt water circulates. However, the location of the concentration sensor 33 is not particularly limited as long as it can detect the salt concentration of the salt water B supplied to the cooler 23.
　また、貯留タンク３１には、タンク内の塩水Ｂおよび氷スラリーＳを撹拌する撹拌羽根３１１と、撹拌羽根３１１を回転させるモーター３１２と、が設置されている。これにより、貯留タンク３１内での氷スラリーＳの凝集を抑制することができる。また、貯留タンク３１には、タンク内に貯留された氷スラリーＳを排出するための排出管３１３が設置されている。 Further, the storage tank 31 is provided with a stirring blade 311 for stirring the salt water B and the ice slurry S in the tank, and a motor 312 for rotating the stirring blade 311. This makes it possible to suppress the aggregation of the ice slurry S in the storage tank 31. Further, the storage tank 31 is provided with a discharge pipe 313 for discharging the ice slurry S stored in the tank.
　冷却システム１の運転中は、ポンプ３２の駆動により貯留タンク３１内の塩水Ｂが配管３４１を通って冷却機２３に供給される。冷却機２３内に供給された塩水Ｂは、冷却機２３内の液冷媒Ｒｌとの熱交換により冷却される。冷却機２３で冷却された塩水Ｂは、配管３４２を通って貯留タンク３１に戻され、再び配管３４１を通って冷却機２３に供給される。また、冷却により生成された氷スラリーＳは、貯留タンク３１に貯留される。塩水循環路３は、このような塩水循環サイクルを繰り返すことにより、氷スラリーＳを連続的に生成する。 During the operation of the cooling system 1, the salt water B in the storage tank 31 is supplied to the cooler 23 through the pipe 341 by driving the pump 32. The salt water B supplied into the cooler 23 is cooled by heat exchange with the liquid refrigerant Rl in the cooler 23. The salt water B cooled by the cooler 23 is returned to the storage tank 31 through the pipe 342, and is supplied to the cooler 23 again through the pipe 341. Further, the ice slurry S generated by cooling is stored in the storage tank 31. The salt water circulation path 3 continuously produces the ice slurry S by repeating such a salt water circulation cycle.
　また、冷却システム１は、冷却システム１の各部の駆動を制御する制御装置４を有する。制御装置４は、例えば、コンピューターから構成され、情報を処理するプロセッサーと、プロセッサーに通信可能に接続されたメモリーと、を有する。メモリーには冷却システム１の運転に必要な各種プログラムが保存されている。プロセッサーは、メモリーに記憶された各種プログラム等を読み込んで実行する。これにより、以下に説明するような冷却システム１の運転が実現される。 Further, the cooling system 1 has a control device 4 that controls the drive of each part of the cooling system 1. The control device 4 includes, for example, a processor composed of a computer and processing information, and a memory communicably connected to the processor. Various programs necessary for operating the cooling system 1 are stored in the memory. The processor reads and executes various programs and the like stored in the memory. As a result, the operation of the cooling system 1 as described below is realized.
　次に、冷却機２３について説明する。図２に示すように、冷却機２３は、メイン蒸発器２３１と、サブ蒸発器２３５と、メイン蒸発器２３１内の液冷媒Ｒｌの圧力を検出する圧力センサー２３９と、を有する。そして、メイン蒸発器２３１の下端部に配管２５２が接続され、サブ蒸発器２３５の上端部に配管２５３が接続されている。凝縮器２２で高圧液状となった液冷媒Ｒｌは、配管２５２を通ってメイン蒸発器２３１に供給される。メイン蒸発器２３１で塩水Ｂとの熱交換により蒸発・気化した低圧ガス状の冷媒Ｒは、サブ蒸発器２３５から配管２５３を通って圧縮機２１に戻される。 Next, the cooler 23 will be described. As shown in FIG. 2, the cooler 23 includes a main evaporator 231, a sub-evaporator 235, and a pressure sensor 239 that detects the pressure of the liquid refrigerant Rl in the main evaporator 231. The pipe 252 is connected to the lower end of the main evaporator 231 and the pipe 253 is connected to the upper end of the sub-evaporator 235. The liquid refrigerant Rl, which has become a high-pressure liquid in the condenser 22, is supplied to the main evaporator 231 through the pipe 252. The low-pressure gaseous refrigerant R evaporated and vaporized by heat exchange with the salt water B in the main evaporator 231 is returned from the sub-evaporator 235 to the compressor 21 through the pipe 253.
　メイン蒸発器２３１は、外管２３２と、外管２３２の内側に同軸的に配置された内管２３３と、を有する。外管２３２および内管２３３は、それぞれ、両端が閉止した円管である。ただし、外管２３２および内管２３３は、それぞれ、円管に限定されない。また、外管２３２および内管２３３は、立てて設置され、軸が鉛直方向を向く。つまり、メイン蒸発器２３１は、竪置き型二重管式蒸発器である。 The main evaporator 231 has an outer pipe 232 and an inner pipe 233 coaxially arranged inside the outer pipe 232. The outer pipe 232 and the inner pipe 233 are circular pipes whose ends are closed, respectively. However, the outer pipe 232 and the inner pipe 233 are not limited to circular pipes, respectively. Further, the outer pipe 232 and the inner pipe 233 are installed upright, and the shaft faces in the vertical direction. That is, the main evaporator 231 is a vertical double-tube evaporator.
　また、メイン蒸発器２３１は、満液式の蒸発器であり、外管２３２と内管２３３との間のスペースのほぼ全部が液冷媒Ｒｌで満たされる。なお、以下では当該スペースを「冷媒貯留部２３４」とも言う。一方、塩水Ｂは、内管２３３内を流れる。そのため、内管２３３の壁面を介して塩水Ｂと液冷媒Ｒｌとの熱交換が行われる。満液式のメイン蒸発器２３１では、液冷媒Ｒｌが内管２３３の外周面に直に接するため、従来技術で述べた乾式と比べて高い仕事効率を発揮でき、液冷媒Ｒｌと塩水Ｂとの熱交換効率を高めることができる。そのため、氷スラリーＳを効率的に生成することができる。 Further, the main evaporator 231 is a full-liquid evaporator, and almost the entire space between the outer pipe 232 and the inner pipe 233 is filled with the liquid refrigerant Rl. In the following, the space will also be referred to as "refrigerant storage unit 234". On the other hand, the salt water B flows in the inner pipe 233. Therefore, heat exchange between the salt water B and the liquid refrigerant Rl is performed through the wall surface of the inner pipe 233. In the full-liquid type main evaporator 231, since the liquid refrigerant Rl is in direct contact with the outer peripheral surface of the inner pipe 233, higher work efficiency can be exhibited as compared with the dry type described in the prior art, and the liquid refrigerant Rl and the salt water B can be combined. The heat exchange efficiency can be increased. Therefore, the ice slurry S can be efficiently generated.
　液冷媒Ｒｌと塩水Ｂとの熱交換効率を高めるために、内管２３３は、鉄、銅、アルミニウム、チタン、ステンレス鋼等、機械的強度に優れかつ熱伝導率の高い材料で構成することが好ましい。また、液冷媒Ｒｌと塩水Ｂとの熱交換効率を高めるために、内管２３３は、機械的強度を保てる限りにおいてなるべく薄肉であることが好ましい。 In order to improve the heat exchange efficiency between the liquid refrigerant Rl and the salt water B, the inner pipe 233 may be made of a material having excellent mechanical strength and high thermal conductivity, such as iron, copper, aluminum, titanium, and stainless steel. preferable. Further, in order to increase the heat exchange efficiency between the liquid refrigerant Rl and the salt water B, the inner pipe 233 is preferably as thin as possible as long as the mechanical strength can be maintained.
　サブ蒸発器２３５は、メイン蒸発器２３１と水平方向に並んで設置されている。サブ蒸発器２３５は、両端が閉止された円管である。また、サブ蒸発器２３５は、立てて設置され、その軸が鉛直方向を向く。このようなサブ蒸発器２３５は、一対の配管２３６を介して冷媒貯留部２３４に接続されている。そのため、冷媒貯留部２３４に供給された液冷媒Ｒｌは、これら配管２３６を通ってサブ蒸発器２３５にも供給される。なお、サブ蒸発器２３５と冷媒貯留部２３４の圧力（内圧）は互いに等しく、サブ蒸発器２３５内の液冷媒Ｒｌの液面高さは、冷媒貯留部２３４内の液冷媒Ｒｌの液面高さと等しい。 The sub-evaporator 235 is installed side by side with the main evaporator 231 in the horizontal direction. The sub-evaporator 235 is a circular tube with both ends closed. Further, the sub-evaporator 235 is installed upright, and its axis faces in the vertical direction. Such a sub-evaporator 235 is connected to the refrigerant storage unit 234 via a pair of pipes 236. Therefore, the liquid refrigerant Rl supplied to the refrigerant storage unit 234 is also supplied to the sub-evaporator 235 through these pipes 236. The pressures (internal pressures) of the sub-evaporator 235 and the refrigerant storage unit 234 are equal to each other, and the liquid level height of the liquid refrigerant Rl in the sub-evaporator 235 is the same as the liquid level height of the liquid refrigerant Rl in the refrigerant storage unit 234. equal.
　また、サブ蒸発器２３５の下端は、メイン蒸発器２３１の下端よりも鉛直方向上側に位置する。そのため、例えば、下端がメイン蒸発器２３１の下端と同じ高さの場合やメイン蒸発器２３１の下端よりも鉛直方向下側に位置する場合と比べて、サブ蒸発器２３５内の液冷媒Ｒｌの量を少なくすることができる。その結果、冷媒Ｒの使用量を削減することができる。また、サブ蒸発器２３５は、メイン蒸発器２３１よりも縦に長く、その上端がメイン蒸発器２３１の上端よりも鉛直方向上側に位置する。そのため、サブ蒸発器２３５内には、液冷媒Ｒｌの上方に位置するスペース２３７が形成される。後述するように、当該スペース２３７には除湿部材２３８が配置される。 Further, the lower end of the sub-evaporator 235 is located above the lower end of the main evaporator 231 in the vertical direction. Therefore, for example, the amount of the liquid refrigerant Rl in the sub-evaporator 235 is higher than the case where the lower end is at the same height as the lower end of the main evaporator 231 or the lower end is located below the lower end of the main evaporator 231 in the vertical direction. Can be reduced. As a result, the amount of the refrigerant R used can be reduced. Further, the sub-evaporator 235 is vertically longer than the main evaporator 231 and its upper end is located vertically above the upper end of the main evaporator 231. Therefore, a space 237 located above the liquid refrigerant Rl is formed in the sub-evaporator 235. As will be described later, a dehumidifying member 238 is arranged in the space 237.
　ここで、メイン蒸発器２３１での塩水Ｂとの熱交換により蒸発・気化した冷媒Ｒは、サブ蒸発器２３５の上端部から配管２５３を通って圧縮機２１に戻される。この際、冷却機２３で蒸発しきれずに液体（湿気）を含んだ状態の冷媒Ｒが圧縮機２１に戻されると、液圧縮による急激なシリンダー内圧上昇によって圧縮機２１が故障する原因となる。そこで、サブ蒸発器２３５のスペース２３７内には気化した冷媒Ｒに含まれる液体（湿気）を除去するための除湿部材２３８が配置されている。 Here, the refrigerant R evaporated and vaporized by heat exchange with the salt water B in the main evaporator 231 is returned to the compressor 21 from the upper end of the sub-evaporator 235 through the pipe 253. At this time, if the refrigerant R in a state of containing liquid (moisture) that cannot be completely evaporated by the cooler 23 is returned to the compressor 21, the compressor 21 may fail due to a sudden increase in the cylinder internal pressure due to the liquid compression. Therefore, a dehumidifying member 238 for removing the liquid (humidity) contained in the vaporized refrigerant R is arranged in the space 237 of the sub-evaporator 235.
　除湿部材２３８は、多数の貫通孔が形成された傘状をなす。このような除湿部材２３８では貫通孔が冷媒Ｒの通路となる。気化した冷媒Ｒは、液面から配管２５３に向けて上昇する途中で除湿部材２３８と接触し、当該接触により冷媒Ｒに含まれる液体（湿気）が除去され、より乾燥した状態の冷媒Ｒが圧縮機２１に戻される。これにより、上述のような圧縮機２１の故障を防ぐことができる。図２の構成では、除湿部材２３８を鉛直方向に複数並べることにより、除湿効果を向上させている。なお、塩水Ｂとの熱交換により冷媒Ｒがほぼ完全に蒸発し、十分に乾いたガス状の冷媒Ｒが圧縮機２１に戻る場合等には除湿部材２３８を省略してもよい。また、例えば、除湿部材２３８では乾燥が不十分となる場合等、除湿部材２３８に替えてまたは加えて、配管２５３の途中に過熱器を配置し、過熱器で冷媒Ｒを加熱してから圧縮機２１に戻す構成としてもよい。 The dehumidifying member 238 has an umbrella shape with a large number of through holes formed. In such a dehumidifying member 238, the through hole serves as a passage for the refrigerant R. The vaporized refrigerant R comes into contact with the dehumidifying member 238 while rising from the liquid surface toward the pipe 253, and the liquid (humidity) contained in the refrigerant R is removed by the contact, and the drier refrigerant R is compressed. It is returned to the machine 21. This makes it possible to prevent the compressor 21 from failing as described above. In the configuration of FIG. 2, a plurality of dehumidifying members 238 are arranged in the vertical direction to improve the dehumidifying effect. The dehumidifying member 238 may be omitted when the refrigerant R is almost completely evaporated by heat exchange with the salt water B and the sufficiently dry gaseous refrigerant R returns to the compressor 21. Further, for example, when the dehumidifying member 238 is insufficiently dried, a superheater is arranged in the middle of the pipe 253 in place of or in addition to the dehumidifying member 238, and the refrigerant R is heated by the superheater before the compressor. It may be configured to return to 21.
　次に、液面計測部２４について説明する。図２に示すように、液面計測部２４は、冷媒貯留管２４１と、液面検出センサー２４２と、を有する。冷媒貯留管２４１は、サブ蒸発器２３５と水平方向に並んで設置されている。また、冷媒貯留管２４１は、立てて設置され、その軸が鉛直方向を向く。また、冷媒貯留管２４１は、一対の配管２４３を介してサブ蒸発器２３５と接続されている。そのため、冷媒貯留部２３４に供給された液冷媒Ｒｌは、サブ蒸発器２３５を介して冷媒貯留管２４１にも供給される。 Next, the liquid level measuring unit 24 will be described. As shown in FIG. 2, the liquid level measuring unit 24 includes a refrigerant storage pipe 241 and a liquid level detection sensor 242. The refrigerant storage pipe 241 is installed side by side with the sub-evaporator 235 in the horizontal direction. Further, the refrigerant storage pipe 241 is installed upright, and its axis faces in the vertical direction. Further, the refrigerant storage pipe 241 is connected to the sub-evaporator 235 via a pair of pipes 243. Therefore, the liquid refrigerant Rl supplied to the refrigerant storage unit 234 is also supplied to the refrigerant storage pipe 241 via the sub-evaporator 235.
　冷媒貯留管２４１、サブ蒸発器２３５および冷媒貯留部２３４内の圧力（内圧）は、互いに等しい。そのため、図２中の鎖線で示すように、冷媒貯留管２４１、サブ蒸発器２３５および冷媒貯留部２３４内の液冷媒Ｒｌの液面高さが互いに等しい。したがって、冷媒貯留管２４１内の液冷媒Ｒｌの液面高さを検出することにより、冷媒貯留部２３４内の液冷媒Ｒｌの液面高さを検出することができる。そこで、冷媒貯留管２４１に液面検出センサー２４２を設置し、液面検出センサー２４２によって冷媒貯留管２４１内の液冷媒Ｒｌの液面高さを検出することにより、冷媒貯留部２３４内の液冷媒Ｒｌの液面高さを検出する構成となっている。このように、冷媒貯留部２３４と異なる場所に液面検出センサー２４２を設置することにより、液冷媒Ｒｌと塩水Ｂとの熱交換を阻害することなく、冷媒貯留部２３４内の液冷媒Ｒｌの液面高さを検出することができる。ただし、液面計測部２４の構成としては、冷媒貯留部２３４内の液冷媒Ｒｌの液面高さを検出することができれば、特に限定されない。 The pressures (internal pressures) in the refrigerant storage pipe 241 and the sub-evaporator 235 and the refrigerant storage unit 234 are equal to each other. Therefore, as shown by the chain line in FIG. 2, the liquid level heights of the liquid refrigerants Rl in the refrigerant storage pipe 241 and the sub-evaporator 235 and the refrigerant storage unit 234 are equal to each other. Therefore, by detecting the liquid level height of the liquid refrigerant Rl in the refrigerant storage pipe 241, it is possible to detect the liquid level height of the liquid refrigerant Rl in the refrigerant storage unit 234. Therefore, a liquid level detection sensor 242 is installed in the refrigerant storage pipe 241, and the liquid level of the liquid refrigerant Rl in the refrigerant storage pipe 241 is detected by the liquid level detection sensor 242, whereby the liquid refrigerant in the refrigerant storage unit 234 is detected. It is configured to detect the liquid level height of Rl. By installing the liquid level detection sensor 242 at a location different from the refrigerant storage unit 234 in this way, the liquid of the liquid refrigerant Rl in the refrigerant storage unit 234 is not hindered from heat exchange between the liquid refrigerant Rl and the salt water B. The surface height can be detected. However, the configuration of the liquid level measuring unit 24 is not particularly limited as long as the liquid level height of the liquid refrigerant Rl in the refrigerant storage unit 234 can be detected.
　なお、冷媒貯留管２４１は、両端が閉止された円管であり、その長さおよび径がサブ蒸発器２３５よりも小さい。このように、冷媒貯留管２４１をサブ蒸発器２３５よりも小さくすることにより、冷媒貯留管２４１内の液冷媒Ｒｌの量を少なくすることができる。その結果、冷媒Ｒの使用量を削減することができる。 The refrigerant storage pipe 241 is a circular pipe with both ends closed, and its length and diameter are smaller than those of the sub-evaporator 235. By making the refrigerant storage pipe 241 smaller than the sub-evaporator 235 in this way, the amount of the liquid refrigerant Rl in the refrigerant storage pipe 241 can be reduced. As a result, the amount of the refrigerant R used can be reduced.
　次に、液面調整バルブ２６について説明する。液面調整バルブ２６は、メイン蒸発器２３１への液冷媒Ｒｌの供給量を制御するためのバルブであり、メイン蒸発器２３１の上流側に設置されている。液面調整バルブ２６は、ＯＮ／ＯＦＦのみならず、０～１００％の開度で多段階または無段階に調整可能である。液面調整バルブ２６の駆動は、制御装置４により制御される。 Next, the liquid level adjusting valve 26 will be described. The liquid level adjusting valve 26 is a valve for controlling the supply amount of the liquid refrigerant Rl to the main evaporator 231 and is installed on the upstream side of the main evaporator 231. The liquid level adjusting valve 26 can be adjusted not only on / off but also in multiple steps or steplessly with an opening degree of 0 to 100%. The drive of the liquid level adjusting valve 26 is controlled by the control device 4.
　制御装置４は、冷却システム１の運転中、液面検出センサー２４２の出力が示す冷媒貯留部２３４内の液冷媒Ｒｌの液面高さＤａと、制御目標である目標液面高さＤｔと、を一致させるフィードバック制御を実行する。これにより、冷媒貯留部２３４内の液冷媒Ｒｌの液面高さＤａを目標液面高さＤｔに保つことができ（目標液面高さＤｔとの乖離を抑制することができ）、液冷媒Ｒｌと塩水Ｂとの熱交換を所望の条件で安定して行うことができる。そのため、氷スラリーＳを安定的かつ効率的に生成することができる。また、生成される氷スラリーＳがより均質なものとなり、高品質な氷スラリーＳを生成することができる。 During the operation of the cooling system 1, the control device 4 determines the liquid level height Da of the liquid refrigerant Rl in the refrigerant storage unit 234 indicated by the output of the liquid level detection sensor 242, the target liquid level height Dt which is the control target, and the target liquid level height Dt. Perform feedback control to match. As a result, the liquid level height Da of the liquid refrigerant Rl in the refrigerant storage unit 234 can be maintained at the target liquid level height Dt (difference from the target liquid level height Dt can be suppressed), and the liquid refrigerant can be suppressed. The heat exchange between Rl and the salt water B can be stably performed under desired conditions. Therefore, the ice slurry S can be stably and efficiently produced. In addition, the ice slurry S produced becomes more homogeneous, and high-quality ice slurry S can be produced.
　特に、制御装置４は、図３に示すように、アナログ制御、特にＰＩＤ制御によって液面調整バルブ２６の駆動を制御する。具体的には、制御装置４は、液面高さＤａと目標液面高さＤｔとの偏差Ｄｅ、偏差Ｄｅの積分および偏差Ｄｅの微分を使用して液面高さＤａについてのＰＩＤ制御を実行する。なお、図３において、比例ゲインＫｐｐ、積分ゲインＫｐｉ、微分ゲインＫｐｄを示す。ＰＩＤ制御によれば、単純なＯＮ／ＯＦＦ制御と比べて液冷媒Ｒｌの液面高さＤａの変動が低減され、液面高さＤａが安定する。したがって、液冷媒Ｒｌと塩水Ｂとの熱交換を所望の条件でより安定して行うことができる。そのため、氷スラリーＳを安定的かつ効率的に生成することができる。また、生成される氷スラリーＳがより均質なものとなり、高品質な氷スラリーＳを生成することができる。ただし、液面調整バルブ２６の制御方法は、特に限定されず、例えば、Ｐ制御、ＰＩ制御等の他のアナログ制御であってもよいし、デジタル制御であってもよい。 In particular, as shown in FIG. 3, the control device 4 controls the drive of the liquid level adjusting valve 26 by analog control, particularly PID control. Specifically, the control device 4 controls the PID for the liquid level height Da by using the deviation De between the liquid level height Da and the target liquid level Dt, the integral of the deviation De, and the derivative of the deviation De. Run. Note that FIG. 3 shows the proportional gain Kpp, the integrated gain Kpi, and the differential gain Kpd. According to the PID control, the fluctuation of the liquid level height Da of the liquid refrigerant Rl is reduced and the liquid level height Da is stabilized as compared with the simple ON / OFF control. Therefore, heat exchange between the liquid refrigerant Rl and the salt water B can be performed more stably under desired conditions. Therefore, the ice slurry S can be stably and efficiently produced. In addition, the ice slurry S produced becomes more homogeneous, and high-quality ice slurry S can be produced. However, the control method of the liquid level adjusting valve 26 is not particularly limited, and may be, for example, other analog control such as P control or PI control, or may be digital control.
　次に、圧力調整バルブ２７について説明する。圧力調整バルブ２７は、メイン蒸発器２３１内の液冷媒Ｒｌの圧力を制御するためのバルブであり、メイン蒸発器２３１の上流側に設置されている。高温高圧ガス状のガス冷媒Ｒｇを高圧液状の液冷媒Ｒｌに供給することにより冷媒貯留部２３４に流入する液冷媒Ｒｌの圧力を高めることができ、圧力調整バルブ２７でガス冷媒Ｒｇの供給量を調整することにより、冷媒貯留部２３４内の液冷媒Ｒｌの圧力を制御することができる。このような制御方法によれば、簡単な構成で、冷媒貯留部２３４内の液冷媒Ｒｌの圧力を制御することができる。 Next, the pressure adjusting valve 27 will be described. The pressure adjusting valve 27 is a valve for controlling the pressure of the liquid refrigerant Rl in the main evaporator 231 and is installed on the upstream side of the main evaporator 231. By supplying the high-temperature high-pressure gaseous gas refrigerant Rg to the high-pressure liquid liquid refrigerant Rl, the pressure of the liquid refrigerant Rl flowing into the refrigerant storage unit 234 can be increased, and the supply amount of the gas refrigerant Rg can be increased by the pressure adjusting valve 27. By adjusting, the pressure of the liquid refrigerant Rl in the refrigerant storage unit 234 can be controlled. According to such a control method, the pressure of the liquid refrigerant Rl in the refrigerant storage unit 234 can be controlled with a simple configuration.
　このような圧力調整バルブ２７は、ＯＮ／ＯＦＦのみならず、０～１００％の開度で多段階または無段階に調整可能である。圧力調整バルブ２７の駆動は、制御装置４により制御される。制御装置４は、冷却システム１の運転中、圧力センサー２３９の出力が示す冷媒貯留部２３４内の液冷媒Ｒｌの圧力Ｐａと、制御目標である目標圧力Ｐｔと、を一致させるフィードバック制御を実行する。 Such a pressure adjusting valve 27 can be adjusted not only on / off but also in multiple steps or steplessly with an opening degree of 0 to 100%. The drive of the pressure adjusting valve 27 is controlled by the control device 4. During the operation of the cooling system 1, the control device 4 executes feedback control for matching the pressure Pa of the liquid refrigerant Rl in the refrigerant storage unit 234 indicated by the output of the pressure sensor 239 with the target pressure Pt, which is the control target. ..
　ここで、液冷媒Ｒｌの温度は、その圧力に比例する。したがって、液冷媒Ｒｌの圧力を制御することは、液冷媒Ｒｌの温度を制御することと同意である。そのため、このようなフィードバック制御を実行することにより、冷媒貯留部２３４内の液冷媒Ｒｌの温度Ｔａを目標温度Ｔｔに保つことができ（目標温度Ｔｔとの乖離を抑制することができ）、液冷媒Ｒｌと塩水Ｂとの熱交換を所望の条件で安定して行うことができる。そのため、氷スラリーＳを安定的かつ効率的に生成することができる。また、生成される氷スラリーＳがより均質なものとなり、高品質な氷スラリーＳを生成することができる。 Here, the temperature of the liquid refrigerant Rl is proportional to its pressure. Therefore, controlling the pressure of the liquid refrigerant Rl is synonymous with controlling the temperature of the liquid refrigerant Rl. Therefore, by executing such feedback control, the temperature Ta of the liquid refrigerant Rl in the refrigerant storage unit 234 can be maintained at the target temperature Tt (difference from the target temperature Tt can be suppressed), and the liquid can be suppressed. The heat exchange between the refrigerant Rl and the salt water B can be stably performed under desired conditions. Therefore, the ice slurry S can be stably and efficiently produced. In addition, the ice slurry S produced becomes more homogeneous, and high-quality ice slurry S can be produced.
　ここで、目標温度Ｔｔ（液冷媒Ｒｌの温度Ｔａ）と、メイン蒸発器２３１に供給される塩水Ｂの凝固点Ｔｆ（氷点）と、の関係について説明する。目標温度Ｔｔが低いほど、つまり、冷媒貯留部２３４内の液冷媒Ｒｌが低温であるほど、液冷媒Ｒｌの仕事量が大きくなり、塩水Ｂをより短時間で冷却することができる。しかしながら、塩水Ｂが凝固点Ｔｆ付近まで冷却された状態においては、目標温度Ｔｔと凝固点Ｔｆの温度差ΔＴが大きすぎるとメイン蒸発器２３１内で塩水Ｂが凍結し、内管２３３の内壁に氷が付着するおそれが高くなる。内管２３３の内壁に氷が付着して成長を続けると、内管２３３内の容積が次第に小さくなり、それに合わせて塩水Ｂの冷却効率が次第に低下し、最終的には内管２３３が塞がって塩水Ｂの循環が不能となる。 Here, the relationship between the target temperature Tt (temperature Ta of the liquid refrigerant Rl) and the freezing point Tf (freezing point) of the salt water B supplied to the main evaporator 231 will be described. The lower the target temperature Tt, that is, the lower the temperature of the liquid refrigerant Rl in the refrigerant storage unit 234, the greater the workload of the liquid refrigerant Rl, and the salt water B can be cooled in a shorter time. However, in a state where the salt water B is cooled to the vicinity of the freezing point Tf, if the temperature difference ΔT between the target temperature Tt and the freezing point Tf is too large, the salt water B freezes in the main evaporator 231 and ice forms on the inner wall of the inner pipe 233. The risk of adhesion increases. When ice adheres to the inner wall of the inner pipe 233 and continues to grow, the volume inside the inner pipe 233 gradually decreases, and the cooling efficiency of the salt water B gradually decreases accordingly, and finally the inner pipe 233 is blocked. The circulation of salt water B becomes impossible.
　このように、内管２３３の内壁に氷が付着し易い条件で運転する場合は、例えば、内管２３３内に、内管２３３の内壁に付着した氷を削り取るための回転ブレード等を設置したり、また、内管２３３の内壁に付着した氷を解かすための作業（デフロスト）を定期的に行ったりする必要がある。これらは、装置構成の煩雑化および高コスト化を招いたり、氷スラリーＳの生成効率を悪化させたりする原因となる。また、塩水Ｂの安定した冷却が阻害され、不均質な氷スラリーＳが生成され易くなる。 In this way, when operating under conditions where ice easily adheres to the inner wall of the inner pipe 233, for example, a rotating blade or the like for scraping off the ice adhering to the inner wall of the inner pipe 233 may be installed in the inner pipe 233. In addition, it is necessary to periodically perform work (defrost) for melting the ice adhering to the inner wall of the inner pipe 233. These cause the apparatus configuration to be complicated and costly, and the efficiency of producing the ice slurry S to be deteriorated. In addition, stable cooling of the salt water B is hindered, and an inhomogeneous ice slurry S is likely to be generated.
　そこで、塩水Ｂが凝固点Ｔｆ付近まで冷却された状態においては、温度差ΔＴが大きくなり過ぎないように目標温度Ｔｔを設定することが好ましい。具体的には、Ｔｆ－１０℃≦Ｔｔ≦Ｔｆであることが好ましく、Ｔｆ－１０℃≦Ｔｔ≦Ｔｆ－３℃であることがより好ましく、Ｔｆ－１０℃≦Ｔｔ≦Ｔｆ－５℃であることがさらに好ましい。つまり、Ｔｆ－１０℃≦Ｔａ≦Ｔｆの関係を満足するように液冷媒Ｒｌの温度を制御することが好ましく、Ｔｆ－８℃≦Ｔａ≦Ｔｆ－３℃の関係を満足するように液冷媒Ｒｌの温度を制御することがより好ましく、Ｔｆ－７℃≦Ｔａ≦Ｔｆ－５℃の関係を満足するように液冷媒Ｒｌの温度を制御することがさらに好ましい。 Therefore, when the salt water B is cooled to the vicinity of the freezing point Tf, it is preferable to set the target temperature Tt so that the temperature difference ΔT does not become too large. Specifically, Tf-10 ° C.≤Tt≤Tf is preferable, Tf-10 ° C.≤Tt≤Tf-3 ° C. is more preferable, and Tf-10 ° C.≤Tt≤Tf-5 ° C. is more preferable. Is even more preferable. That is, it is preferable to control the temperature of the liquid refrigerant Rl so as to satisfy the relationship of Tf-10 ° C.≤Ta≤Tf, and the liquid refrigerant Rl so as to satisfy the relationship of Tf-8 ° C.≤Ta≤Tf-3 ° C. It is more preferable to control the temperature of the liquid refrigerant Rl, and it is further preferable to control the temperature of the liquid refrigerant Rl so as to satisfy the relationship of Tf-7 ° C ≤ Ta ≤ Tf-5 ° C.
　温度差ΔＴをこのような範囲とすることにより、塩水Ｂの凍結を抑制しつつ、より大きな温度差で塩水Ｂを冷却することができる。そのため、内管２３３の内壁に氷が付着し難くなり、長時間にわたって安定して氷スラリーＳを連続生成することができる。なお、冷却システム１では、仕事効率の高い満液式のメイン蒸発器２３１を用いているため、温度差ΔＴを小さくても高い仕事量を確保することができ、塩水Ｂを十分な速度で冷却することが可能となる。つまり、満液式のメイン蒸発器２３１を用いるからこそ小さい温度差ΔＴによる運転が実現される。また、冷却システム１によれば、液冷媒Ｒｌの温度をち密にコントロールすることができるため、温度差ΔＴを精度よく制御することができる。 By setting the temperature difference ΔT in such a range, it is possible to cool the salt water B with a larger temperature difference while suppressing freezing of the salt water B. Therefore, it becomes difficult for ice to adhere to the inner wall of the inner tube 233, and the ice slurry S can be stably generated for a long period of time. Since the cooling system 1 uses a full-liquid main evaporator 231 with high work efficiency, a high work amount can be secured even if the temperature difference ΔT is small, and the salt water B is cooled at a sufficient speed. It becomes possible to do. That is, the operation with a small temperature difference ΔT is realized because the full-liquid main evaporator 231 is used. Further, according to the cooling system 1, since the temperature of the liquid refrigerant Rl can be closely controlled, the temperature difference ΔT can be controlled accurately.
　制御装置４による圧力調整バルブ２７の駆動制御の説明に戻る。塩水Ｂの凝固点Ｔｆは、塩分濃度で定まるため、塩水Ｂの塩分濃度が分かれば塩水Ｂの凝固点Ｔｆが求まる。そこで、制御装置４は、まず、濃度センサー３３の出力が示す冷却機２３内の塩水Ｂの塩分濃度から塩水Ｂの凝固点Ｔｆを求める。次に、制御装置４は、温度差ΔＴが所定値となるように液冷媒Ｒｌの目標温度Ｔｔを設定する。次に、制御装置４は、設定した目標温度Ｔｔに対応する液冷媒Ｒｌの圧力を求め、これを目標圧力Ｐｔとして設定する。 Return to the explanation of the drive control of the pressure adjustment valve 27 by the control device 4. Since the freezing point Tf of the salt water B is determined by the salt concentration, the freezing point Tf of the salt water B can be obtained if the salt concentration of the salt water B is known. Therefore, the control device 4 first obtains the freezing point Tf of the salt water B from the salt concentration of the salt water B in the cooler 23 indicated by the output of the concentration sensor 33. Next, the control device 4 sets the target temperature Tt of the liquid refrigerant Rl so that the temperature difference ΔT becomes a predetermined value. Next, the control device 4 obtains the pressure of the liquid refrigerant Rl corresponding to the set target temperature Tt, and sets this as the target pressure Pt.
　制御装置４は、アナログ制御、特にＰＩＤ制御によって圧力調整バルブ２７の駆動を制御する。具体的には、制御装置４は、図４に示すように、圧力Ｐａと目標圧力Ｐｔとの偏差Ｐｅ、偏差Ｐｅの積分および偏差Ｐｅの微分を使用して圧力ＰａについてのＰＩＤ制御を実行する。図４において、比例ゲインＫｐｐ、積分ゲインＫｐｉ、微分ゲインＫｐｄを示す。ＰＩＤ制御によれば、単純なＯＮ／ＯＦＦ制御と比べて冷媒Ｒの圧力Ｐａの変動が低減され、圧力Ｐａが安定する。したがって、液冷媒Ｒｌと塩水Ｂとの熱交換を所望の条件でより安定して行うことができる。そのため、氷スラリーＳを安定的かつ効率的に生成することができる。また、生成される氷スラリーＳがより均質なものとなり、高品質な氷スラリーＳを生成することができる。ただし、圧力調整バルブ２７の制御方法は、特に限定されず、例えば、Ｐ制御、ＰＩ制御等の他のアナログ制御であってもよいし、デジタル制御であってもよい。 The control device 4 controls the drive of the pressure adjusting valve 27 by analog control, particularly PID control. Specifically, as shown in FIG. 4, the control device 4 executes PID control for the pressure Pa by using the deviation Pe between the pressure Pa and the target pressure Pt, the integral of the deviation Pe, and the derivative of the deviation Pe. .. FIG. 4 shows the proportional gain Kpp, the integrated gain Kpi, and the differential gain Kpd. According to the PID control, the fluctuation of the pressure Pa of the refrigerant R is reduced and the pressure Pa is stabilized as compared with the simple ON / OFF control. Therefore, heat exchange between the liquid refrigerant Rl and the salt water B can be performed more stably under desired conditions. Therefore, the ice slurry S can be stably and efficiently produced. In addition, the ice slurry S produced becomes more homogeneous, and high-quality ice slurry S can be produced. However, the control method of the pressure adjusting valve 27 is not particularly limited, and may be, for example, other analog control such as P control or PI control, or may be digital control.
　ここで、制御装置４は、冷却機２３内での塩水Ｂの凍結（内管２３３への氷の付着）を抑制しつつ、効率的に塩水Ｂを冷却するために複数の圧力制御モードを有する。本実施形態では、複数の圧力制御モードとして、急冷モードＭ１と徐冷モードＭ２とを有する。徐冷モードＭ２は、前述した制御モードであり、Ｔｆ－１０℃≦Ｔａ≦Ｔｆとなるように圧力調整バルブ２７の駆動を制御するモードである。一方、急冷モードＭ１は、徐冷モードＭ２よりも温度Ｔａを低くし、より大きな温度差ΔＴとなるように圧力調整バルブ２７の駆動を制御するモードである。したがって、急冷モードＭ１の方が徐冷モードＭ２よりも液冷媒Ｒｌの仕事量が大きく塩水Ｂの冷却能力が高い。 Here, the control device 4 has a plurality of pressure control modes in order to efficiently cool the salt water B while suppressing freezing of the salt water B (adhesion of ice to the inner pipe 233) in the cooler 23. .. In the present embodiment, as a plurality of pressure control modes, a quenching mode M1 and a slow cooling mode M2 are provided. The slow cooling mode M2 is the control mode described above, and is a mode in which the drive of the pressure adjusting valve 27 is controlled so that Tf −10 ° C. ≦ Ta ≦ Tf. On the other hand, the quenching mode M1 is a mode in which the temperature Ta is lower than that of the slow cooling mode M2, and the drive of the pressure adjusting valve 27 is controlled so as to have a larger temperature difference ΔT. Therefore, the quenching mode M1 has a larger work load of the liquid refrigerant Rl than the slow cooling mode M2, and the cooling capacity of the salt water B is higher.
　制御装置４は、凝固点Ｔｆ以上の温度を閾値ＳＨとし、塩水Ｂの温度が閾値ＳＨ以上では急冷モードＭ１で圧力調整バルブ２７の駆動を制御し、塩水Ｂの温度が閾値ＳＨ未満では徐冷モードＭ２で圧力調整バルブ２７の駆動を制御する。これにより、塩水Ｂが凍結するおそれが低い状態では急冷モードＭ１で塩水Ｂを短時間で冷却し、塩水Ｂの温度が凝固点Ｔｆに近づき凍結するおそれが高くなってきたら徐冷モードＭ２で塩水Ｂを穏やかに安定して冷却することができる。このように、急冷モードＭ１と徐冷モードＭ２とを切り替えることにより、塩水Ｂの凍結を抑制しつつ、できるだけ大きい温度差（凍結しないぎりぎりの温度差）で塩水Ｂを冷却することができる。そのため、内管２３３内への氷の付着を抑制しつつ、より短時間で塩水Ｂを冷却することができる。そのため、氷スラリーＳの生成効率が向上する。 The control device 4 sets the temperature above the freezing point Tf as the threshold value SH, controls the drive of the pressure adjusting valve 27 in the quenching mode M1 when the temperature of the salt water B is above the threshold value SH, and slow-cools mode when the temperature of the salt water B is less than the threshold value SH. The drive of the pressure adjusting valve 27 is controlled by M2. As a result, when the risk of freezing of the salt water B is low, the salt water B is cooled in a short time in the quenching mode M1, and when the temperature of the salt water B approaches the freezing point Tf and the risk of freezing increases, the salt water B is cooled in the slow cooling mode M2. Can be cooled gently and stably. In this way, by switching between the quenching mode M1 and the slow cooling mode M2, the salt water B can be cooled with the largest possible temperature difference (the temperature difference just before freezing) while suppressing the freezing of the salt water B. Therefore, the salt water B can be cooled in a shorter time while suppressing the adhesion of ice into the inner pipe 233. Therefore, the production efficiency of the ice slurry S is improved.
　閾値ＳＨとしては、特に限定されず、各部の性能によっても異なるが、例えば、凝固点Ｔｆよりも０℃～７℃高い温度とすることが好ましく、凝固点Ｔｆよりも３℃～５℃高い温度とすることがより好ましい。これにより、塩水Ｂの凍結を抑制しつつ、急冷モードＭ１で塩水Ｂをより低温まで冷却することができるため、塩水Ｂをより短時間で冷却することができ、氷スラリーＳの生成効率が向上する。なお、制御装置４は、急冷モードＭ１および徐冷モードＭ２以外の駆動モードを有していてもよい。また、制御装置４は、徐冷モードＭ２だけを有していてもよい。 The threshold value SH is not particularly limited and varies depending on the performance of each part, but for example, the temperature is preferably 0 ° C. to 7 ° C. higher than the freezing point Tf and 3 ° C. to 5 ° C. higher than the freezing point Tf. Is more preferable. As a result, the salt water B can be cooled to a lower temperature in the quenching mode M1 while suppressing the freezing of the salt water B, so that the salt water B can be cooled in a shorter time and the production efficiency of the ice slurry S is improved. do. The control device 4 may have a drive mode other than the quenching mode M1 and the slow cooling mode M2. Further, the control device 4 may have only the slow cooling mode M2.
　以上、冷却システム１について説明した。このような冷却システム１を用いれば、例えば、海水を原料とした氷スラリーＳを連続的に生成することができる。このため、冷却システム１を例えば漁船や漁港等に設置し、冷却システム１で生成した氷スラリーＳを鮮魚の保冷等に利用することができる。この場合、鮮魚の保冷のために消費された氷スラリーＳの量に見合う量の新たな海水が図示しない補給ポンプにより貯留タンク３１に補給される構成とすればよい。氷スラリーＳによれば鮮魚を傷付けることなく長時間保冷することが可能となる。 The cooling system 1 has been described above. By using such a cooling system 1, for example, an ice slurry S made from seawater can be continuously generated. Therefore, the cooling system 1 can be installed in, for example, a fishing boat or a fishing port, and the ice slurry S generated by the cooling system 1 can be used for keeping fresh fish cold. In this case, the storage tank 31 may be replenished with fresh seawater in an amount commensurate with the amount of ice slurry S consumed for keeping the fresh fish cold by a replenishment pump (not shown). According to the ice slurry S, it is possible to keep the fresh fish cold for a long time without damaging it.
　＜第２実施形態＞
　本実施形態は、内管２３３内に撹拌装置５を設置したこと以外は、前述した第１実施形態と同様である。なお、以下の説明では、本実施形態に関し、前述した実施形態との相違点を中心に説明し、同様の事項に関してはその説明を省略する。また、図５において、前述した実施形態と同様の構成については、同一符号を付している。 <Second Embodiment>
This embodiment is the same as the first embodiment described above, except that the stirring device 5 is installed in the inner pipe 233. In the following description, the present embodiment will be mainly described with respect to the differences from the above-described embodiment, and the description thereof will be omitted for the same matters. Further, in FIG. 5, the same reference numerals are given to the same configurations as those of the above-described embodiment.
　図５に示すように、本実施形態の冷却システム１は、前述した第１実施形態の構成に加えて、冷却機２３内の塩水Ｂを撹拌する撹拌装置５を有する。撹拌装置５は、内管２３３の中心軸に沿って配置された回転軸５１と、回転軸５１を回転させるモーター５２と、回転軸５１に固定された複数の羽根５３と、を有する。また、各羽根５３は、その先端が内管２３３の内周面に接触している。回転軸５１を回転させると羽根５３が回転し、内管２３３内を流れる塩水Ｂに渦巻状の対流が生じる。そのため、液冷媒Ｒｌと塩水Ｂとの熱交換効率が高まり、塩水Ｂをより効率的に冷却することができる。また、内管２３３の内周面に氷が付着しても、羽根５３によってその氷を掻き取ることができる。そのため、内管２３３の内周面での氷の成長が抑えられ、氷スラリーＳの生成効率の低下を抑制することができる。 As shown in FIG. 5, the cooling system 1 of the present embodiment has a stirring device 5 for stirring the salt water B in the cooler 23, in addition to the configuration of the first embodiment described above. The stirring device 5 has a rotating shaft 51 arranged along the central axis of the inner pipe 233, a motor 52 for rotating the rotating shaft 51, and a plurality of blades 53 fixed to the rotating shaft 51. Further, the tip of each blade 53 is in contact with the inner peripheral surface of the inner pipe 233. When the rotation shaft 51 is rotated, the blades 53 rotate, and spiral convection occurs in the salt water B flowing in the inner pipe 233. Therefore, the heat exchange efficiency between the liquid refrigerant Rl and the salt water B is increased, and the salt water B can be cooled more efficiently. Further, even if ice adheres to the inner peripheral surface of the inner pipe 233, the ice can be scraped off by the blade 53. Therefore, the growth of ice on the inner peripheral surface of the inner tube 233 can be suppressed, and the decrease in the production efficiency of the ice slurry S can be suppressed.
　なお、撹拌装置５の構成は、これに限定されず、例えば、各羽根５３は、内管２３３の内周面と非接触であってもよい。各羽根５３と内周面とを非接触とすることにより、内管２３３や羽根５３の寸法精度が要求されないため、装置構成がより簡単となる。 The configuration of the stirring device 5 is not limited to this, and for example, each blade 53 may be non-contact with the inner peripheral surface of the inner pipe 233. By making each blade 53 and the inner peripheral surface non-contact, the dimensional accuracy of the inner pipe 233 and the blade 53 is not required, so that the device configuration becomes simpler.
　以上、本発明の運転制御方法および冷却システムについて、図示の実施形態に基づいて説明したが、本発明はこれに限定されるものではない。例えば、各部の構成は、同様の機能を発揮する任意の構成のものに置換することができ、また、任意の構成を付加することもできる。また、各実施形態を適宜組み合わせてもよい。 Although the operation control method and the cooling system of the present invention have been described above based on the illustrated embodiment, the present invention is not limited thereto. For example, the configuration of each part can be replaced with an arbitrary configuration that exhibits the same function, or an arbitrary configuration can be added. Moreover, you may combine each embodiment as appropriate.
　なお、前述した実施形態では、被冷却媒体として塩水Ｂを用いたが、被冷却媒体としては、これに限定されない。例えば、各種飲料水や塩化カルシウム水溶液等の各種水溶液であってもよい。また、冷却システム１は、氷スラリーＳを生成する用途に限定されず、例えば、液体、特に、水、清涼飲料水、牛乳、果実ジュース、野菜ジュース、アルコール飲料等の各種飲料水を未凍結のまま冷却することに用いてもよい。つまり、冷却システム１は、冷却システムとして用いられてもよい。また、冷却システム１は、目的の装置や試料を冷却するためのチラー（冷却水循環装置）として用いられてもよい。 In the above-described embodiment, the salt water B is used as the cooling medium, but the cooling medium is not limited to this. For example, it may be various aqueous solutions such as various drinking waters and calcium chloride aqueous solutions. Further, the cooling system 1 is not limited to the application for producing the ice slurry S, and for example, liquids, particularly water, soft drinks, milk, fruit juices, vegetable juices, alcoholic drinks and other various drinking waters are unfrozen. It may be used for cooling as it is. That is, the cooling system 1 may be used as a cooling system. Further, the cooling system 1 may be used as a chiller (cooling water circulation device) for cooling a target device or sample.
　以上のように、液冷媒Ｒ１との熱交換により被冷却媒体としての塩水Ｂを冷却する冷却機２３を有する冷却システム１の運転制御方法は、液冷媒Ｒｌに高圧ガス状のガス冷媒Ｒｇを供給することにより、冷却機２１内での液冷媒Ｒ１の温度を制御する。そのため、冷媒貯留部２３４内の液冷媒Ｒｌの温度Ｔａを目標温度Ｔｔに保つことができ（目標温度Ｔｔとの乖離を抑制することができ）、液冷媒Ｒｌと塩水Ｂとの熱交換を所望の条件で安定して行うことができる。これにより、氷スラリーＳを安定的かつ効率的に生成することができる。また、生成される氷スラリーＳがより均質なものとなり、高品質な氷スラリーＳを生成することができる。したがって、その産業上の利用可能性は大きい。 As described above, the operation control method of the cooling system 1 having the cooler 23 for cooling the salt water B as the cooling medium by heat exchange with the liquid refrigerant R1 supplies the liquid refrigerant Rl with the high-pressure gaseous gas refrigerant Rg. By doing so, the temperature of the liquid refrigerant R1 in the cooler 21 is controlled. Therefore, the temperature Ta of the liquid refrigerant Rl in the refrigerant storage unit 234 can be maintained at the target temperature Tt (difference from the target temperature Tt can be suppressed), and heat exchange between the liquid refrigerant Rl and the salt water B is desired. It can be performed stably under the conditions of. Thereby, the ice slurry S can be stably and efficiently produced. In addition, the ice slurry S produced becomes more homogeneous, and high-quality ice slurry S can be produced. Therefore, its industrial applicability is great.
　１…冷却システム、２…冷媒回路、２１…圧縮機、２２…凝縮器、２２１…送風ファン、２３…冷却機、２３１…メイン蒸発器、２３２…外管、２３３…内管、２３４…冷媒貯留部、２３５…サブ蒸発器、２３６…配管、２３７…スペース、２３８…除湿部材、２３９…圧力センサー、２４…液面計測部、２４１…冷媒貯留管、２４２…液面検出センサー、２４３…配管、２５１…配管、２５２…配管、２５３…配管、２５４…配管、２６…液面調整バルブ、２７…圧力調整バルブ、３…塩水循環路、３１…貯留タンク、３１１…撹拌羽根、３１２…モーター、３１３…排出管、３２…ポンプ、３３…濃度センサー、３４１…配管、３４２…配管、４…制御装置、５…撹拌装置、５１…回転軸、５２…モーター、５３…羽根、Ｂ…塩水、Ｄａ…液面高さ、Ｄｅ…偏差、Ｄｔ…目標液面高さ、Ｋｐｄ…微分ゲイン、Ｋｐｉ…積分ゲイン、Ｋｐｐ…比例ゲイン、Ｐａ…圧力、Ｐｅ…偏差、Ｐｔ…目標圧力、Ｒ…冷媒、Ｒｇ…ガス冷媒、Ｒｌ…液冷媒、Ｓ…氷スラリー 1 ... Cooling system, 2 ... Refrigerator circuit, 21 ... Compressor, 22 ... Condenser, 221 ... Blower fan, 23 ... Cooler, 231 ... Main evaporator, 232 ... Outer pipe, 233 ... Inner pipe, 234 ... Refrigerator storage Department, 235 ... Sub-evaporator, 236 ... Piping, 237 ... Space, 238 ... Dehumidifying member, 239 ... Pressure sensor, 24 ... Liquid level measuring unit, 241 ... Refrigerator storage pipe, 242 ... Liquid level detection sensor, 243 ... Piping, 251 ... Piping, 252 ... Piping, 253 ... Piping, 254 ... Piping, 26 ... Liquid level adjusting valve, 27 ... Pressure adjusting valve, 3 ... Salt water circulation path, 31 ... Storage tank, 311 ... Stirring blade, 312 ... Motor, 313 ... Discharge pipe, 32 ... Pump, 33 ... Concentration sensor, 341 ... Piping, 342 ... Piping, 4 ... Control device, 5 ... Stirring device, 51 ... Rotating shaft, 52 ... Motor, 53 ... Blade, B ... Salt water, Da ... Liquid level height, De ... deviation, Dt ... target liquid level height, Kpd ... differential gain, Kpi ... integrated gain, Kpp ... proportional gain, Pa ... pressure, Pe ... deviation, Pt ... target pressure, R ... refrigerant, Rg ... Gas piping, Rl ... Liquid piping, S ... Ice slurry

Claims (10)

  1. 　液冷媒との熱交換により被冷却媒体を冷却する冷却機を有する冷却システムの運転制御方法であって、
    　前記液冷媒に高圧ガス状のガス冷媒を供給することにより、前記冷却機内での前記液冷媒の温度を制御することを特徴とする運転制御方法。     It is an operation control method of a cooling system having a cooler that cools a medium to be cooled by heat exchange with a liquid refrigerant.
    An operation control method comprising controlling the temperature of the liquid refrigerant in the cooler by supplying a high-pressure gaseous gas refrigerant to the liquid refrigerant.
  2. 　冷媒を圧縮機で圧縮することにより前記ガス冷媒を生成し、
    　前記ガス冷媒を凝縮器で凝縮することにより前記液冷媒を生成する請求項１に記載の運転制御方法。     The gas refrigerant is generated by compressing the refrigerant with a compressor.
    The operation control method according to claim 1, wherein the liquid refrigerant is generated by condensing the gas refrigerant with a condenser.
  3. 　前記冷却機内の前記液冷媒の圧力に基づいて前記液冷媒に供給する前記ガス冷媒の量をフィードバック制御する請求項１または２に記載の運転制御方法。 The operation control method according to claim 1 or 2, wherein the amount of the gas refrigerant supplied to the liquid refrigerant is feedback-controlled based on the pressure of the liquid refrigerant in the cooler.
  4. 　前記液冷媒に供給する前記ガス冷媒の量をＰＩＤ制御により制御する請求項３に記載の運転制御方法。 The operation control method according to claim 3, wherein the amount of the gas refrigerant supplied to the liquid refrigerant is controlled by PID control.
  5. 　前記液冷媒の温度をＴａ（℃）とし、前記被冷却媒体の凝固点をＴｆ（℃）としたとき、
    　Ｔｆ－１０℃≦Ｔａ≦Ｔｆの関係を満足するように前記液冷媒の温度を制御する請求項１から４のいずれか１項に記載の運転制御方法。     When the temperature of the liquid refrigerant is Ta (° C) and the freezing point of the medium to be cooled is Tf (° C),
    The operation control method according to any one of claims 1 to 4, wherein the temperature of the liquid refrigerant is controlled so as to satisfy the relationship of Tf-10 ° C.≤Ta≤Tf.
  6. 　Ｔｆ－１０℃≦Ｔａ≦Ｔｆの関係を満足するように前記液冷媒の温度を制御する徐冷モードと、前記徐冷モードよりもＴａが低くなるように前記液冷媒の温度を制御する急冷モードと、を有し、
    　前記被冷却媒体の温度が閾値以上のときは前記急冷モードで前記液冷媒の温度を制御し、
    　前記被冷却媒体の温度が前記閾値未満のときは前記徐冷モードで前記液冷媒の温度を制御する請求項５に記載の運転制御方法。     A slow cooling mode in which the temperature of the liquid refrigerant is controlled so as to satisfy the relationship of Tf-10 ° C. ≤ Ta ≤ Tf, and a quenching mode in which the temperature of the liquid refrigerant is controlled so that Ta is lower than the slow cooling mode. And have
    When the temperature of the medium to be cooled is equal to or higher than the threshold value, the temperature of the liquid refrigerant is controlled in the quenching mode.
    The operation control method according to claim 5, wherein when the temperature of the medium to be cooled is less than the threshold value, the temperature of the liquid refrigerant is controlled in the slow cooling mode.
  7. 　前記冷却機内の前記液冷媒の量が制御目標となるように、前記冷却機内に供給される前記液冷媒の量を制御する請求項１から６のいずれか１項に記載の運転制御方法。 The operation control method according to any one of claims 1 to 6, wherein the amount of the liquid refrigerant supplied into the cooler is controlled so that the amount of the liquid refrigerant in the cooler becomes a control target.
  8. 　前記冷却機内の前記液冷媒の量に基づいて前記冷却機に供給する前記液冷媒の量をフィードバック制御する請求項７に記載の運転制御方法。 The operation control method according to claim 7, wherein the amount of the liquid refrigerant supplied to the cooler is feedback-controlled based on the amount of the liquid refrigerant in the cooler.
  9. 　前記冷却機に供給する前記液冷媒の量をＰＩＤ制御により制御する請求項８に記載の運転制御方法。 The operation control method according to claim 8, wherein the amount of the liquid refrigerant supplied to the cooler is controlled by PID control.
  10. 　冷媒を圧縮して高圧ガス状のガス冷媒とする圧縮機と、
    　前記ガス冷媒を凝縮して高圧液状の液冷媒とする凝縮器と、
    　前記液冷媒との熱交換により被冷却媒体を冷却する冷却機と、
    　前記液冷媒に前記ガス冷媒を供給することにより、前記冷却機内における前記液冷媒の温度を制御する制御装置と、を有することを特徴とする冷却システム。     A compressor that compresses the refrigerant into a high-pressure gaseous gas refrigerant,
    A condenser that condenses the gas refrigerant into a high-pressure liquid liquid refrigerant,
    A cooler that cools the medium to be cooled by heat exchange with the liquid refrigerant, and
    A cooling system comprising: a control device for controlling the temperature of the liquid refrigerant in the cooler by supplying the gas refrigerant to the liquid refrigerant.
PCT/JP2021/046894 2020-12-25 2021-12-19 Operation control method and cooling system WO2022138520A1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04251176A (en) * 1990-12-29 1992-09-07 Daikin Ind Ltd Ice making device
JP2000055495A (en) * 1998-08-05 2000-02-25 Sanyo Electric Co Ltd Air conditioner provided with ice heat storage tank
JP2001033109A (en) * 1999-07-21 2001-02-09 Daikin Ind Ltd Refrigerator
JP2004148966A (en) * 2002-10-30 2004-05-27 Denso Corp Refrigeration cycle apparatus

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04251176A (en) * 1990-12-29 1992-09-07 Daikin Ind Ltd Ice making device
JP2000055495A (en) * 1998-08-05 2000-02-25 Sanyo Electric Co Ltd Air conditioner provided with ice heat storage tank
JP2001033109A (en) * 1999-07-21 2001-02-09 Daikin Ind Ltd Refrigerator
JP2004148966A (en) * 2002-10-30 2004-05-27 Denso Corp Refrigeration cycle apparatus

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