Phase change determination system

Abstract

The present disclosure addresses the problem of providing a phase change determination system capable of determining the occurrence of a phase change. A phase change determination system (1) is provided with: a temperature sensor (31) for acquiring the temperature of a coolant (21); a database (43) for storing a reference temperature set in association with the coolant (21); and a determination unit (47) that determines whether or not the phase change has occurred in the coolant (21) on the basis of the acquisition results of the temperature sensor (31) and the reference temperature. The reference temperature includes a first reference temperature set to be lower than the freezing point of the coolant 21, and the determination unit 47 determines that the coolant 21 begins to solidify by changing to rise within a temperature interval lower than the first reference temperature according to the acquisition result of the temperature sensor 31.

Description

Technical Field

[0001] This invention relates to a phase transition determination system. Background Technology

[0002] Historically, cold storage materials have been commonly used for items requiring low-temperature preservation for refrigeration or freezing (hereinafter referred to as "refrigerated items"). For example, the cold storage material disclosed in Patent Document 1 comprises a shell and a liquid or gel-like cold storage agent filled within the shell. When used in a frozen state, the cold storage material achieves refrigeration and cold preservation through the latent heat released when the cold storage agent changes from a solid to a liquid state. By using different types of cold storage agents with different freezing points (melting points), the temperature range within which the cold storage material can achieve cold preservation can be adjusted.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2014-219184 Summary of the Invention

[0006] The problem that this invention aims to solve

[0007] However, since the appearance of the aforementioned cold storage materials changes little during the phase change of the cold storage agent, it is difficult to determine the exact time when the cold storage agent is completely frozen.

[0008] Therefore, the purpose of this invention is to provide a phase transition determination system capable of determining when a phase transition has occurred.

[0009] Problem Solving Methods

[0010] This invention provides a system for determining whether an object has undergone a phase transition, comprising:

[0011] Temperature acquisition unit for obtaining the temperature of the object;

[0012] A storage unit that stores a reference temperature set in relation to the object;

[0013] A determination unit that determines whether a phase transition has occurred in an object based on the acquired temperature and a reference temperature.

[0014] The reference temperature includes a first reference temperature set below the freezing point of the object; when the temperature below the first reference temperature begins to rise based on the results obtained by the temperature acquisition unit, the determination unit determines that the object has begun to solidify. This system is called a phase change determination system.

[0015] Invention Effects

[0016] According to the present invention, a phase transition determination system capable of determining the occurrence of a phase transition can be provided. Attached Figure Description

[0017] 【 Figure 1 The diagram shows the overall structure of the phase transition determination system 1 in this embodiment.

[0018] 【 Figure 2 The figure shows the cooling test results for the cold storage plate 20A.

[0019] 【 Figure 3 The figure shows the results of the cooling test on the cold storage plate 20B.

[0020] 【 Figure 4 The figure shows the results of the cooling test on the cold storage plate at 20°C.

[0021] 【 Figure 5 The flowchart of the phase transition determination process is displayed.

[0022] 【 Figure 6 [This is a schematic diagram showing the state of frozen food 70 stored in the freezer 60 in other embodiments.]

[0023] Figure Labels

[0024] 1. Phase transition determination system

[0025] 20 Cold storage plate (cold storage component)

[0026] 21. Coolant (Object)

[0027] 30, 80 RFID tags (memory section, temperature acquisition section)

[0028] 31 Temperature Sensor (Temperature Acquisition Unit)

[0029] 43 Database (Memory Section)

[0030] 47 Judgment Department

[0031] 70 Frozen Desserts (Object) Detailed Implementation

[0032] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0033] The phase change determination system 1 described in this embodiment is used to determine whether a phase change has occurred in the cold storage plate 20 filled with cold storage agent 21 when the cold storage plate 20 is cooled.

[0034] The cold storage plate 20 is used to refrigerate the refrigerated items and belongs to the cold storage component. The cold storage plate 20 includes a hollow box-shaped shell 22 and a cold storage agent 21 filled in the shell 22.

[0035] The refrigerant 21 is mainly based on water with a high latent heat of melting, with appropriate amounts of refrigerant and gelling agent added. Nucleating agents, colorants, and preservatives may also be added if necessary. The freezing point (melting point) of the refrigerant 21 can be appropriately set by adjusting the type and amount of refrigerant, thereby adjusting the temperature range that the cold storage plate 20 can maintain. The freezing point of the refrigerant 21 filled in the cold storage plate 20 is set, for example, to 0℃, -3℃, or -22℃. Hereinafter, the cold storage plate 20 with a freezing point of 0℃ is referred to as "cold storage plate 20A", the one with a freezing point of -3℃ is referred to as "cold storage plate 20B", and the one with a freezing point of -22℃ is referred to as "cold storage plate 20C".

[0036] Furthermore, the cold storage agent 21 in this embodiment differs from general cold insulation agents composed of highly absorbent resins. Instead, it is formulated with sodium chloride and a gelling agent. Therefore, the cold storage agent 21 has moderate viscosity, can stably maintain a gel-like state, and easily remains constant within the target temperature range. Also, unlike general cold insulation agents, the cold storage agent 21 in this embodiment is composed of components capable of long-term cold retention. Therefore, the cold storage plate 20 of this embodiment exhibits superior long-term constant temperature maintenance performance compared to ordinary cold insulation agents. For example, the registered trademark "IceBattery" of Innovation Thru Energy Co., Ltd. can be used as such a cold storage plate 20.

[0037] The phase transition determination system 1 includes: a cooling device 10, an RFID tag 30, a temperature sensor 31, a reader / writer 35, and a management terminal 40.

[0038] The cooling device 10 is an ultra-low temperature freezer. The cooling device 10 includes a square box-shaped main body 10a, a cover 10b that can be opened and closed and connected to the main body 10a, and a storage space 11 enclosed by the main body 10a and the cover 10b.

[0039] The cooling device 10 can cool the storage space 11 to a set target temperature. The storage space 11 can accommodate one or more cold storage plates 20. With the cold storage plates 20 housed in the cooling device 10, the storage space 11 can be cooled to a set temperature. This set temperature can be set below the freezing point of the cold storage agent 21.

[0040] RFID tag 30 is a tag used to implement radio frequency identification (RFID), specifically a passive tag. RFID tags 30 are, for example, respectively disposed on each of the cold storage plates 20.

[0041] Temperature sensor 31 is used to acquire the temperature of the refrigerant 21, and is for example, built into the housing 22. Temperature sensor 31 corresponds to the temperature acquisition unit.

[0042] The RFID tag 30 and the temperature sensor 31 can communicate with each other, and the RFID tag 30 can gradually acquire the measurement results of the temperature sensor 31.

[0043] The RFID tag 30 can store various information, especially identification information related to the refrigerant 21 (hereinafter referred to as "identification information"). For example, the identification information can be set for each refrigerant plate 20 containing the refrigerant 21.

[0044] The RFID tag 30 sends a signal (referred to as the "first signal") that includes the acquisition results and identification information of the temperature sensor 31 to the outside.

[0045] The reader 35 communicates wirelessly with the RFID tag 30. The reader 35 is positioned where it can transmit and receive signals with the RFID tag 30, for example, within the storage space 11. The reader 35 sends a signal to the RFID tag 30 requesting it to send a first signal (referred to as the "second signal"). Upon receiving the second signal, the RFID tag 30 sends the first signal. The RFID tag 30 operates by receiving radio waves emitted by the reader 35 as its power source.

[0046] The reader 35 communicates wirelessly with the management terminal 40. After receiving the first signal, the reader 35 sends the information contained in the first signal to the management terminal 40. Therefore, the measurement result and identification information of the temperature sensor 31 are input to the management terminal 40.

[0047] The management terminal 40 includes a display 41 for displaying various information, a speaker 42 for voice output, a database 43, a communication unit 44, a timer 45, and a control unit 46.

[0048] Database 43 is a storage device for storing various types of information, such as ROM, RAM, flash memory, solid-state drive (SSD), or hard disk drive (HDD). Database 43 corresponds to the storage unit.

[0049] The communication unit 44 is used to communicate with external devices. The communication unit 44 communicates with the cooling device 10 and the reader / writer 35, receiving measurement results from the temperature sensor 31 and various information stored in the RFID tag 30 sent from the reader / writer 35. After receiving external information, it inputs that information to the control unit 46.

[0050] Timer 45 is used to measure time. Timer 45 measures the elapsed time from a certain moment, for example, if the measurement result is reset, the time is remeasured from that reset moment.

[0051] The control unit 46 performs various control processes. The functions of the control unit 46 are realized by expanding the software unique to this embodiment into RAM or the like for processing through a computing device such as a CPU mounted in the management terminal 40.

[0052] The control unit 46 can control the cooling device 10, including changing the set temperature and controlling the on / off state of the cooling device 10.

[0053] The control unit 46 also includes a determination unit 47 for performing various determinations. When cooling the cold storage plate 20, the control unit 46 (determination unit 47) performs a process to determine whether the cold storage agent 21 has undergone a phase change (hereinafter referred to as "phase change determination process").

[0054] The control unit 46 stores the information input through the communication unit 44 and the phase transition determination processing results into the database 43. Simultaneously, as mentioned earlier, it controls the cooling device 10.

[0055] Here, the cold storage plate 20 is used in principle with the cold storage agent 21 completely solidified. Before use, the cold storage plate 20 needs to be cooled by the cooling device 10. The phase change determination system 1 determines the time point when the cold storage agent 21 begins to solidify and when solidification is completed through phase change determination processing.

[0056] Since the temperature of the refrigerant 21 during phase change varies depending on its type, a cooling test (hereinafter referred to as the "cooling test") was conducted to measure the temperature change of the refrigerant 21 over time by cooling the refrigerant plate 20 using the cooling device 10. The results of the cooling test are referenced... Figures 2 to 4 Please provide an explanation. Figures 2-4 In the figure, the horizontal axis represents the elapsed time (in hours) from when the cooling device 10 starts cooling the storage space 11, and the vertical axis represents the temperature of the refrigerant 21 (in °C). Figure 2 The results of the cooling test of the cold storage plate 20A are as follows: Figure 3 The results of the cooling test for the cold storage plate 20B are as follows. Figure 4 These are the cooling test results for the cold storage plate at 20°C. The temperature was set at an ultra-low temperature (-50°C) during the test.

[0057] In the cooling test of the cold storage plate 20A, such as Figure 2 As shown, the temperature of the refrigerant 21 is higher than the freezing point (0°C) at the beginning, and it is in a completely liquid state.

[0058] Subsequently, the temperature of the refrigerant 21 dropped to 0°C and continued to drop to a supercooled state.

[0059] Then, at a certain point in time, the temperature starts to rise, that is, it changes from falling to rising, indicating that the coolant 21 begins to solidify.

[0060] The temperature then rises rapidly to near the freezing point and remains relatively constant (with a slight decrease) in the temperature range near the freezing point.

[0061] Afterwards, the temperature of the coolant 21 drops sharply, indicating that solidification is complete. "Complete solidification" refers to the state in which the object has completely transformed from a liquid to a solid.

[0062] Afterward, the temperature of the coolant 21 drops to a certain fixed value and remains stable.

[0063] For cold storage plate 20B (see...) Figure 3 ), cold storage plate 20C (see Figure 4 Similar temperature change processes were also observed.

[0064] Phase transition determination system 1 performs phase transition determination processing, which will be further explained below.

[0065] When performing phase transition determination, a reference temperature must be set. The reference temperature includes a first reference temperature and a second reference temperature. For example, the first and second reference temperatures can be set based on cooling test results.

[0066] The first reference temperature is set to a temperature below the freezing point, for example, the freezing point of the refrigerant 21. Furthermore, the first reference temperature should be set to a temperature not lower than the temperature at which the refrigerant 21 has completely solidified.

[0067] The second reference temperature is set to be lower than the first reference temperature but higher than the temperature at which the refrigerant 21 begins to solidify (the temperature at which the temperature changes from decreasing to increasing). Specifically, the second reference temperature is set to be no higher than the temperature at which the refrigerant 21 completes solidification, and preferably to be the actual temperature at which solidification is complete.

[0068] The first reference temperature and the second reference temperature are stored in database 43. The identification information of the cold storage plate 20, as well as the first reference temperature and the second reference temperature associated with the cold storage agent 21 filled in the cold storage plate 20, are stored in association in database 43.

[0069] The control unit 46 receives the measurement results and identification information from the temperature sensor 31 sequentially via the communication unit 44. The control unit 46 can access the database 43 and read the associated reference temperature in a timely manner based on the received identification information.

[0070] Next, the control unit 46 (determination unit 47) performs phase transition determination processing based on the measurement results of the temperature sensor 31 and the reference temperature. Hereinafter, refer to... Figure 5 Explain the process for phase transition determination. Figure 5The flowchart illustrates the phase change determination process. When the control unit 46 begins controlling the cooling device 10 to perform cooling, the phase change determination process is simultaneously initiated. The phase change determination process is repeated at predetermined time intervals until it is determined in step S20 that the refrigerant 21 has solidified completely. Furthermore, when multiple refrigerant plates 20 are cooled simultaneously, the process shown in the flowchart is performed separately for each refrigerant plate 20 (RFID tag 30).

[0071] In step S11, it is determined whether the second flag (Flag 2) described later is in an on state. If the second flag is on (YES determination), the process proceeds to step S19; if it is off (NO determination), the process proceeds to step S12.

[0072] In step S12, it is determined whether the first flag (Flag 1) described later is in an on state. If the first flag is on (YES determination), proceed to step S17; if it is off (NO determination), proceed to step S13.

[0073] In step S13, it is determined whether the measurement result of the temperature sensor 31 is lower than the first reference temperature. Here, the first reference temperature associated with it is read from the database 43 using identification information as a reference. If the measurement result is lower than the first reference temperature (YES determination), proceed to step S14; if it is higher than the first reference temperature (NO determination), return to step S11 and repeat the subsequent processing.

[0074] In step S14, it is determined whether the measurement result of temperature sensor 31 has turned upward. "Turning upward" means that the latest measurement value is higher than the previous measurement value, and the previous measurement value is not higher than the measurement value before that. If an upward trend is detected (YES determination), proceed to step S15; if it has not turned upward (NO determination), return to step S11 and continue processing. Note: The measurement results of temperature sensor 31 received by management terminal 40 are stored in database 43. Control unit 46 (determination unit 47) accesses database 43 and refers to historical data to make the determination in step S14.

[0075] In step S15, it is determined that the refrigerant 21 has begun to solidify. That is, when the measurement result of the temperature sensor 31 turns upward within the range below the first reference temperature, it is determined that the refrigerant 21 has begun to solidify. In addition, in this step S15, a notification process is performed through the display 41 and the speaker 42 to notify the user that the refrigerant 21 has begun to solidify. Then, the process proceeds to step S16.

[0076] In step S16, Flag 1 is set to ON. Flag 1 indicates that the refrigerant 21 has been determined to begin solidification. Then, proceed to step S17.

[0077] In step S17, it is determined whether the temperature sensor 31's acquisition result is higher than the second reference temperature. Here, the associated second reference temperature is read from the database 43 using identification information. If the temperature sensor 31's acquisition result is higher than the second reference temperature (YES determination), proceed to step S18; if it is lower than or equal to the second reference temperature (NO determination), return to step S11 and continue processing.

[0078] In step S18, the second flag (Flag 2) is set to "on". The second flag indicates that after the refrigerant 21 is determined to have started to solidify, the temperature sensor 31 has obtained a result higher than the second reference temperature. Then, proceed to step S19.

[0079] In step S19, it is determined whether the result obtained by the temperature sensor 31 is lower than or equal to the second reference temperature. Here, the second reference temperature associated with it is read from the database 43 by means of identification information. If the result obtained by the temperature sensor 31 is lower than or equal to the second reference temperature (YES determination), then proceed to step S20; if it is higher than the second reference temperature (NO determination), then return to step S11 and continue processing.

[0080] In step S20, it is determined that the solidification of the refrigerant 21 is complete. That is, after the object is determined to have begun to solidify, and the temperature sensor 31's reading was once higher than the second reference temperature and then dropped below the second reference temperature, it is determined that the refrigerant 21 has completed solidification. Furthermore, in this step S20, a notification process is performed via the display 41 and speaker 42 to notify the user that the refrigerant 21 has completed solidification. Subsequently, this process ends. At the same time, the first flag and the second flag are reset to the off state.

[0081] Furthermore, cooling can be performed even if multiple cold storage plates 20 with different freezing points are simultaneously housed in the cooling device 10. Since each cold storage plate 20 is equipped with an RFID tag 30 and a temperature sensor 31, the phase change progress of each cold storage agent 21 can be monitored separately even when cooling is performed simultaneously.

[0082] According to the detailed description of this embodiment above, the following significant effects can be obtained.

[0083] In this embodiment, the reference temperature includes a first reference temperature set below the freezing point of the refrigerant 21; the determination unit 47 determines that the refrigerant 21 begins to solidify when the temperature range below the first reference temperature turns upward based on the acquisition result of the temperature sensor 31.

[0084] Normally, when a liquid object is cooled, its temperature drops below its freezing point due to supercooling, and then rises again at a certain point in time. This point in time is when the object begins to solidify. This embodiment can accurately pinpoint this point in time and determine that the refrigerant 21 has begun to solidify, providing a system capable of determining when a phase change has occurred.

[0085] In this embodiment, the reference temperature also includes a second reference temperature set below the temperature at which the object is solidified; the determination unit determines that solidification is complete based on the temperature change after the object begins to solidify, and further based on the temperature changing from above the second reference temperature to below the second reference temperature.

[0086] After an object begins to solidify, its temperature rises to near the freezing point and remains stable, then drops again at a certain point in time. This point of temperature drop is the point at which solidification is complete. This invention can pinpoint this point and accurately determine when solidification is complete.

[0087] In this embodiment, the RFID tag 30 stores identification information related to the cold storage agent 21, can acquire data from the temperature sensor 31 and send it to the outside, the database 43 stores the identification information in association with the reference temperature, and the determination unit 47 determines whether a phase change has occurred based on the identification information, the temperature acquisition result and the reference temperature.

[0088] Therefore, even if there are multiple cold storage plates 20, their respective phase change states can be determined separately and accurately.

[0089] In this embodiment, the object to be determined is the cold storage agent 21 used for cold preservation.

[0090] The cold storage plate 20 is typically used after the internal cold storage agent 21 has completely solidified. This invention effectively supports the preparation work for the use of the cold storage plate 20.

[0091] The above is merely a description of the embodiments of the present invention. The present invention is not limited to the above embodiments and can be implemented in various forms without departing from the spirit of the present invention.

[0092] In the above embodiments, the object to be determined is the cold storage agent 21, but it is not limited to this; it can also be frozen dessert 70, such as ice cream, ice cream, milk ice, frozen dessert, etc. Even if the object is composed of a mixture of multiple substances and has different freezing points, its freezing point can be determined in advance through experiments before making the determination.

[0093] In the manufacturing process of frozen desserts, sometimes it is necessary to completely solidify them to stabilize the product's shape or facilitate storage and transportation. For example, as... Figure 6 As shown, after the ice cream is filled into the container, it is placed in the freezing device (equivalent to the cooling device) 60 and cooled at a set temperature (such as -30°C) until it is completely solidified.

[0094] During this process, it is not advisable to frequently open the freezing device, and it is also difficult to judge whether solidification is complete by visual inspection. Therefore, it is traditionally difficult to accurately determine the exact time when solidification is complete.

[0095] However, by using the phase change determination system of the present invention, if an RFID tag and a temperature acquisition component are set in the frozen dessert 70, temperature data can be acquired in real time, and the solidification completion time can also be accurately determined.

[0096] RFID tags can have built-in temperature acquisition capabilities, in which case the RFID tag itself can act as a temperature acquisition unit. Figure 6 In the example, the frozen dessert 70 is equipped with an RFID tag 80 that has temperature acquisition function. Furthermore, the RFID tag 80 does not have to be equipped on all frozen desserts 70; it can be equipped on only some products.

[0097] In the above embodiment, the reference temperature is stored in the database 43, but it can also be stored in the RFID tag itself. In this case, the reference temperature is transmitted to the management terminal 40 along with the temperature acquisition data via the reader 35. The management terminal 40 performs phase transition determination processing based on the received reference temperature and temperature data. In this case, the RFID tag 30 also functions as a memory unit.

[0098] Communication between the temperature acquisition unit and the determination unit can be wireless or wired. For example, the temperature acquisition unit can be a common temperature sensor connected to the determination unit via a wired connection, in which case the RFID tag 30 and reader 35 are not necessary components.

[0099] In the above embodiments, the phase change determination process is performed on the phase change from liquid to solid, but it can also be set to determine the phase change from solid to liquid.

[0100] When an object melts from a solid to a liquid, its temperature first rises and then stabilizes at a certain point in time, before rising again at another point in time. The former is the point at which melting begins, and the latter is the point at which melting is complete.

[0101] Therefore, a third reference temperature (above the freezing point) and a fourth reference temperature (above the third reference temperature) are established. These reference temperatures can be confirmed experimentally and stored in association with identification information.

[0102] The determination unit determines that the object has begun to melt based on the temperature acquisition results reaching the third reference temperature.

[0103] The determination unit, based on the temperature acquisition results, reaches the third reference temperature and then further reaches the fourth reference temperature, determining that the object has completely melted. This allows for the estimation of the point at which the object loses its cooling capacity, such as the moment when the refrigerant 21 completely melts in the refrigerant plate 20.

[0104] Each device can also be implemented via cloud computing. For example, the storage unit can be located on a cloud server, and the management terminal 40 can be a smartphone or other terminal.

[0105] The phase transition determination system 1 can also infer the type of object. For example, the type of object and a first reference temperature can be pre-stored in a database, and the type of object can be inferred based on temperature changes.

[0106] RFID tags can also be placed inside the cold storage plate 20. For example, BLE (Bluetooth Low Energy) tags with low temperature resistance and waterproof performance can be installed, with a service life of 5 to 7 years.

Claims

1. A system for determining whether an object has undergone a phase transition, comprising: Temperature acquisition unit, used to acquire the temperature of the object in question; The storage unit is used to store the reference temperature set in association with the object being described; The determination unit, based on the results obtained by the temperature acquisition unit and the reference temperature, determines whether the object has undergone a phase transition. Its features are: The reference temperature mentioned includes a first reference temperature set below the freezing point of the object mentioned. The determination unit determines that the object has begun to solidify based on the temperature acquisition unit's acquisition results and the fact that the temperature range below the first reference temperature has turned upward.

2. The phase transition determination system according to claim 1, characterized in that: The reference temperature also includes a second reference temperature set below the temperature at which the object has completed solidification. The determination unit determines that the solidification of the object is complete based on the fact that the temperature acquisition unit first obtains a temperature greater than the second reference temperature and then a temperature less than the second reference temperature after the object begins to solidify.

3. A system for determining whether an object has undergone a phase transition, comprising: Temperature acquisition unit, used to acquire the temperature of the object in question; The storage unit is used to store the reference temperature set in association with the object being described; The determination unit, based on the results obtained by the temperature acquisition unit and the reference temperature, determines whether the object has undergone a phase transition. Its features are: The reference temperature mentioned includes a third reference temperature set above the freezing point of the object mentioned. The determination unit determines that the object has begun to melt when the third reference temperature is reached based on the acquisition result of the temperature acquisition unit.

4. The phase transition determination system according to claim 3, characterized in that: The reference temperature also includes a fourth reference temperature that is set higher than the third reference temperature. Based on the results obtained by the temperature acquisition unit, the determination unit determines that the object has completely melted after reaching the third reference temperature and then the fourth reference temperature.

5. The phase transition determination system according to any one of claims 1 to 4, characterized in that: Equipped with RFID tags for storing identification information related to the object; The RFID tag obtains temperature data from the temperature acquisition unit and sends the identification information along with the temperature data to the outside. The storage unit will store the identification information in association with the reference temperature; The determination unit determines whether a phase transition has occurred based on the identification information, temperature data, and reference temperature.

6. The phase transition determination system according to any one of claims 1 to 4, characterized in that: The object being referred to is the refrigerant filled in the cold storage components used for insulation.

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