Temperature control device and control method thereof

Abstract

To provide a temperature adjustment device capable of stably managing temperature during fluctuation of ambient temperature, and provide a control method thereof.SOLUTION: A temperature adjustment device comprises: a housing; a storage container that is stored in the housing, and contains a heat conductive potion that stores a temperature adjustment target; a temperature adjustment unit that includes an upper Peltier element thermally connected to the storage container on a first surface, a lower Peltier element thermally connected to a second surface of the upper Peltier element on the first surface, and a heat radiation fin thermally connected to the second surface of the lower Peltier element; a control device that controls the temperature adjustment unit; and a temperature sensor that measures each temperature on the first surface side of the upper Peltier element and the first surface side of the lower Peltier element. The control device includes a first control unit that controls the upper Peltier element so that a measurement value indicating the temperature on the first surface side of the upper Peltier element becomes a set value, and a second control unit that controls the lower Peltier element so that a measurement value indicating the temperature of the first surface of the lower Peltier element becomes a predetermined reference value.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a temperature control device and a control method thereof, and more particularly to a temperature control device and a control method thereof suitable for maintaining a temperature control target such as a sample or a pharmaceutical within a predetermined temperature range. [Background technology]

[0002] A Peltier element has a heat absorbing surface and a heat dissipating surface, and operates to obtain a temperature difference between the two surfaces. When a commercially available Peltier element is installed in a hot / cold storage unit, the temperature inside the unit is affected by the outside temperature when the Peltier element is operated at full rated power, and the temperature inside the unit is a certain temperature lower than the outside temperature (for example, minus 20°C). Note that the Peltier element can switch between heating and cooling on one side by changing the polarity of the applied voltage. In the following description, for the sake of convenience, it is assumed that the temperature control target is cooled.

[0003] In order to cool the temperature control target without being affected by the outside air temperature, the number of Peltier elements can be increased to increase the cooling capacity. In addition, in order to suppress excessive cooling capacity and perform constant temperature control, feedback control based on the temperature of the temperature control target can be performed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. WO2019 / 187849 Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, in a Peltier element, the driving power for cooling becomes heat, so in addition to the heat absorbed from the temperature control target, the heat generated in the Peltier element must be discharged from the Peltier element. For example, when the outside air temperature rises and the cooling target value approaches the limit of the cooling capacity, the power supplied to the Peltier element increases, and the amount of heat generated by the Peltier element also increases, so that the Peltier element consumes more power.

[0006] Furthermore, for example, if the temperature of the heat dissipation side of the Peltier element changes with fluctuations in the outside air temperature, causing the temperature of the heat absorption side of the Peltier element to fluctuate, the balance of the temperature control is lost, making stable control of the Peltier element difficult.

[0007] Therefore, the present invention aims to provide a temperature control device and a control method thereof that maintains high cooling capacity, reduces the amount of power supplied to the Peltier element even when there is a large difference between the outside air temperature and the target value, and enables stable temperature control when the outside air temperature fluctuates. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the present invention provides: A housing and A storage container that is housed in the housing and that houses a temperature control target and includes a heat conductive portion; a temperature control unit including an upper Peltier element thermally connected to the storage container at a first surface, a lower Peltier element thermally connected to a second surface of the upper Peltier element at a first surface, and a heat dissipation fin thermally connected to the second surface of the lower Peltier element; A control device for controlling the temperature adjustment unit; a temperature sensor for measuring the temperature of each of the first surface side of the upper Peltier element and the first surface side of the lower Peltier element; The control device a first control unit that controls the upper Peltier element so that a measurement value indicating a temperature on a first surface side of the upper Peltier element becomes a set value; a second control unit that controls the lower Peltier element so that a measurement value indicating a temperature of a first surface of the lower Peltier element becomes a predetermined reference value; A temperature control device characterized by to provide.

[0009] In the temperature control device of the present invention, it is preferable that the temperature sensor further measures the temperature inside the storage container, and the first control unit corrects the set value according to a difference between a measured value indicating the temperature inside the storage container and the temperature on the first surface side of the upper Peltier element, and controls the upper Peltier element using the corrected set value. Here, the temperature inside the storage container is a temperature that allows the temperature inside the storage container to be inferred or serves as an index of the temperature inside the storage container, and may be directly measured by a temperature sensor arranged inside the container, or may be indirectly measured, for example, by a temperature sensor arranged on the outer circumferential surface of the storage container located on the opposite side to the temperature control unit.

[0010] In addition, in the temperature control device of the present invention, it is preferable that the temperature sensor further measures the temperature of the outside air, and the second control unit corrects the reference value according to the measured value of the outside air temperature, and controls the lower Peltier element using the corrected reference value.

[0011] In addition, in the temperature control device of the present invention, it is preferable that the first control unit and the second control unit limit the driving power of the upper Peltier element and the lower Peltier element to a predetermined percentage of the maximum set output within a predetermined period from the start of operation of the temperature control unit.

[0012] In the temperature adjustment apparatus of the present invention, it is preferable that, for one or more stages having a plurality of Peltier elements, the control device selects a Peltier element to be driven from the plurality of Peltier elements in accordance with a drive output.

[0013] In the temperature adjustment device of the present invention, it is preferable that the temperature adjustment unit further includes a thermal conductor interposed between the upper Peltier element and the lower Peltier element.

[0014] Furthermore, in the temperature control device of the present invention, it is preferable that the temperature control unit further includes one or more middle-stage Peltier elements thermally connected to the upper-stage Peltier element on a first surface and the lower-stage Peltier element on a second surface, the temperature sensor further measures the temperature of a first surface of the middle-stage Peltier element, and the first control unit controls the middle-stage Peltier element so that a measured value indicating the temperature of the first surface of the middle-stage Peltier element reaches a predetermined temperature difference from the set value.

[0015] In addition, in the temperature adjustment device of the present invention, it is preferable that the weight thereof when driven by a battery is 20 kg or less.

[0016] Moreover, it is preferable that the temperature control device of the present invention further comprises a temperature logger that records the measurement value of the temperature sensor.

[0017] Moreover, the temperature adjustment device of the present invention preferably further comprises wireless or wired communication means for communicating with an external device.

[0018] The present invention also provides a method for producing a method for manufacturing a semiconductor device comprising the steps of: A housing and A storage container that is housed in the housing, stores a temperature control target, and includes a heat conductive portion; a temperature control unit including an upper Peltier element thermally connected to the storage container at a first surface, a lower Peltier element thermally connected to a second surface of the upper Peltier element and the first surface, and a heat dissipation fin thermally connected to the second surface of the lower Peltier element; a temperature sensor for measuring the temperatures of the first surface side of the upper Peltier element and the first surface side of the lower Peltier element; a step of controlling the upper Peltier element so that a measurement value indicating a temperature on a first surface side of the upper Peltier element becomes a set value; a step of controlling the lower Peltier element so that a measurement value indicating a temperature of a first surface of the lower Peltier element becomes a predetermined reference value; The present invention also provides a method for controlling a temperature adjustment device, which comprises the steps of: Effect of the Invention

[0019] According to the temperature control device and control method of the present invention, by using multiple stages of Peltier elements and controlling the Peltier elements in the stage on the heat dissipation fin side to follow a reference value other than the target value of the temperature inside the cabinet, it is possible to achieve precise temperature control while reducing the power consumption of the temperature control unit, even when there is a large difference between the outside air temperature and the target value. [Brief description of the drawings]

[0020] [Figure 1] 1 is a perspective view showing the appearance of a temperature adjustment device 1 according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view of the temperature adjustment device 1 with the lid 11 open. [Diagram 3] 2 is a cross-sectional view taken along line AA in FIG. 1. [Figure 4] FIG. 2 is a functional block diagram of the temperature adjustment device 1. [Diagram 5] 2A to 2C are a perspective view, a side view, and an exploded view showing an outline of a temperature adjustment unit 30. [Figure 6] FIG. 2 is a block diagram showing an outline of a temperature adjustment function. [Figure 7] FIG. 13 is a block diagram showing an outline of control of the number of operating elements. [Figure 8] 3 is a block diagram showing an outline of a minimum load operation of the temperature adjustment device 1. FIG. [Figure 9] 4 is a block diagram showing an outline of a medium load operation of the temperature adjustment device 1. FIG. [Figure 10] 4 is a block diagram showing an outline of the maximum load operation of the temperature adjustment device 1. FIG. [Figure 11] 2 is a block diagram showing an outline of the start-up operation of the temperature adjustment device 1. FIG. [Figure 12] 1 is a flowchart 1 showing the operation of upper and middle Peltier elements 31, 32. [Figure 13] 4 is a flowchart 2 showing the operation of the upper and middle Peltier elements 31, 32. [Figure 14] 13 is a flowchart showing the operation of the lower Peltier element 33. [Figure 15]10 is a graph showing an example of a change in temperature inside a storage compartment in response to a change in outside air temperature. [Figure 16] 1A to 1C are a perspective view, a side view, and an exploded view showing an outline of a temperature adjustment unit 130 in a first modified example of the present embodiment. [Figure 17] 13A to 13C are a perspective view, a side view, and an exploded view showing an outline of a temperature adjustment unit 230 in a second modified example of the present embodiment. [Figure 18] 13A to 13C are a perspective view, a side view, and an exploded view showing an outline of a temperature adjustment unit 330 in a third modified example of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Representative embodiments of the temperature control device and the control method thereof according to the present invention will be described in detail below with reference to the drawings, but the present invention is not limited thereto. The drawings are for conceptually explaining the present invention, and therefore, for ease of understanding, dimensions, ratios, or numbers may be exaggerated or simplified as necessary.

[0022] 1. Overview of temperature control device 1 The temperature control device 1 is preferably used for transporting a temperature control target such as a sample or a pharmaceutical product (including a bioproduct or a blood product) while maintaining the temperature within a preset range. However, the present invention is not limited to a temperature control device involving transportation. The following description is given on the assumption that the temperature control device 1 cools the temperature control target to a set value, but the temperature control device 1 may also heat the temperature control target to a set value.

[0023] The temperature adjustment device 1 includes a housing 10, a heat-conductive storage container 20, a temperature adjustment unit 30, a control device 50, and temperature sensors 41 to 46. A belt (not shown) can be attached to the temperature adjustment device 1 for manual transportation. It is preferable that the temperature adjustment device 1 has a weight of, for example, 14 kg to 20 kg when driven by a battery, so that it can be transported by hand.

[0024] As shown in Fig. 1, the housing 10 has a box shape as a whole. The housing 10 houses the storage container 20, the temperature adjustment unit 30, the control device 50, the temperature sensors 41-46, and other components. As shown in Fig. 2, the housing 10 opens upward to house the storage container 20, and is closed by a heat-insulating lid 11 so as to be freely opened and closed. A heat transfer plate 12 made of metal with excellent heat transfer properties is attached to the inner surface of the lid 11, and the storage space S is configured to be covered with the heat transfer body when the lid 11 is closed.

[0025] The housing 10 and the lid 11 may be made of a synthetic resin such as polypropylene or ABS resin, or a metal. The inside of the housing 10 and the lid 11 are filled with insulating materials 13, 14 formed of, for example, injected rigid urethane foam, vacuum insulating material, polystyrene foam, or a combination thereof.

[0026] As shown in Fig. 3, the storage container 20 is attached to the inside of the housing 10 and forms a storage space S to be temperature-controlled. The storage container 20 opens upward and is closed by a lid 11 so as to be freely opened and closed. The storage container 20 may be made entirely or partially of a heat-conductive metal such as aluminum. Alternatively, a heat-conductive member may be provided separately from the storage container 20. The storage space S may be divided by a partition plate 21.

[0027] The temperature adjustment unit 30 contacts the outer surface of the storage container 20 and maintains the temperature inside the storage space S (i.e., the internal temperature) at a preset target value (i.e., a set value) within a predetermined allowable range. As shown typically in Fig. 4, the temperature adjustment unit 30 includes a plurality of stages of Peltier elements 31-33, thermal conductors 34-36, a heat dissipation fin 37, and a fan (not shown) that blows cooling air to the heat dissipation fin 37.

[0028] As shown in FIG. 5, the temperature control unit 30 has a three-stage configuration including an upper Peltier element 31, a middle Peltier element 32, and a lower Peltier element 33. The upper Peltier element 31, the middle Peltier element 32, and the lower Peltier element 33 are each substantially flat plate-shaped and have upper and lower surfaces (first surface and second surface) that are substantially parallel to and face each other. Although it will be described in detail later, heat conductors 34 and 35 are interposed between the upper Peltier element 31 and the middle Peltier element 32, and between the middle Peltier element 32 and the lower Peltier element 33, respectively. A heat conductor 36 is disposed between the upper Peltier element 31 and the storage container 20 and thermally connects them.

[0029] Here, the roles of the upper Peltier element 31 and the middle Peltier element 32 are to adjust the temperature inside the storage container 20. The role of the lower Peltier element 33 is to keep the heat dissipation sides of the upper Peltier element 31 and the middle Peltier element 32 at a certain temperature.

[0030] The Peltier elements 31 to 33 are plate-shaped semiconductor thermoelectric elements. If the areas of the heat absorption side and the heat dissipation side surfaces of the Peltier elements 31 to 33 are S1, S2, and S3, then S1 ≤ S2 < S3. In this embodiment, S1:S2:S3 = 1:2:4.

[0031] The Peltier elements 31 to 33 include one or more Peltier modules having substantially the same dimensions and the same performance from the viewpoints of ease of control and manufacturing cost. In the example of FIG. 5, the upper Peltier element 31 is composed of one Peltier module, the middle Peltier element 32 is composed of two Peltier modules, and the lower Peltier element 33 is composed of four Peltier modules, respectively.

[0032] The operation of the temperature control unit 30 is controlled by the control device 50. That is, the control device 50 controls the temperature control unit 30 based on the detection signals of the temperature sensors 41 to 46 installed at predetermined positions in the temperature control device 1 so that the temperature inside the storage container 20 falls within the allowable range of the set value.

[0033] The control device 50 has the functions of a first control unit 51, a second control unit 52, a setting unit 53, and a correction unit 54. However, the division into the first control unit 51, the second control unit 52, the setting unit 53, and the correction unit 54 is for convenience, and a certain functional unit (e.g., the first control unit 51) may execute the function of another functional unit (e.g., the second control unit 52).

[0034] The first control unit 51 adjusts the power supplied to the upper stage Peltier element 31 and the middle stage Peltier element 32 in accordance with a predetermined control flow (see FIG. 12 and FIG. 13). The second control unit 52 adjusts the power supplied to the lower stage Peltier element 33 in accordance with a predetermined control flow (see FIG. 14). Details of the control by the first control unit 51 and the second control unit 52 will be described later.

[0035] The setting unit 53 sets a set value, which is a target value of the inside temperature, based on a user input or automatically according to the temperature control target. The setting unit 53 also sets an upper stage target value, which is a target value of the temperature on the heat absorption side of the upper stage Peltier element 31, based on the set value. The upper stage target value may be the same as the set value, or may be set lower than the set value. The setting unit 53 also sets a middle stage target value, which is a target value of the temperature on the heat absorption side of the middle stage Peltier element 31. The middle stage target value is set lower by a predetermined temperature than the upper stage target value. The setting unit 53 sets a reference value, which is a target value of the temperature on the heat absorption side of the lower stage Peltier element 33. The reference value is set to a certain constant value. Details of the processing by the setting unit 53 will be described later.

[0036] The correction unit 54 corrects the set value and the reference value under a predetermined condition. The correction unit 54 may correct the upper target value. The process by the correction unit 54 will be described in detail later.

[0037] In this embodiment, various temperature sensors are used to control the temperature adjustment unit 30. Representative temperature sensors include a temperature sensor 43 that measures the temperature inside the storage container 20 and outputs a measurement value Tx, temperature sensors 42 and 44 that measure the temperatures of the thermal conductors 34 and 35 and output the measurement values ​​Tcp2 and Tcp3, a temperature sensor 45 that measures the temperature of the thermal conductor 36 and output the measurement value Tcp1, a temperature sensor 41 that measures the temperature of the heat dissipation fin 37 and output the measurement value Th, and a temperature sensor 46 that measures the temperature of the outside air and output the measurement value Ta (see FIG. 4). Here, the temperature sensor 43 does not need to directly measure the temperature inside the storage container, and may indirectly measure the temperature of a specific outer surface of the storage container 20 (for example, the outer circumferential surface located on the opposite side to the temperature adjustment unit 30) as a temperature that infers or indicates the temperature inside the storage container. Thermistors and semiconductor sensors can be suitably used as the temperature sensors 41 to 46, but are not limited thereto.

[0038] The temperature data detected by these temperature sensors 41-46 is displayed on the display device 63 and recorded in the storage device 62 together with the sampling time. That is, the storage device 62 functions as a temperature logger. The storage device 62 further stores various settings and control programs for the temperature adjustment device 1. The display device 63 may also function as an input device by being provided with, for example, a touch panel screen.

[0039] The temperature adjustment device 1 has a power supply 63 for supplying power to components such as the temperature adjustment unit 30. The power supply 63 may be an internal battery such as a lithium ion secondary battery, or an external power supply such as a commercial power supply. The temperature adjustment device 1 drives the temperature adjustment unit 30 with power supplied from the internal battery while the temperature adjustment target is being transported, and can charge the internal battery while supplying power to the temperature adjustment unit 30 from an external power supply at the destination such as a hospital.

[0040] Furthermore, the temperature adjustment device 1 has a communication device 64 as a wireless or wired communication means for communicating with an external device (see FIG. 4). For example, the wireless communication unit 64 includes a communication module according to various standards belonging to a wireless PAN (Personal Area Network), a wireless LAN (Local Area Network), a wireless MAN (Metropolitan Area Network), or a wireless WAN (Wide Area Network). Moreover, the wired communication unit 64 includes a communication module according to a standard such as Ethernet. Therefore, the temperature adjustment device 1 can, for example, transmit collected temperature data to an external server, and can receive instructions from an external computer.

[0041] 2. Operation and control method of temperature adjustment unit 30 2-1.Basic operation The upper-stage Peltier element 31 absorbs heat from the storage container 20 via the thermal conductor 36 in order to bring the temperature inside the storage container 20 closer to the set value, and discharges the absorbed heat to the middle-stage thermal conductor 34 together with heat generated by the drive of the upper-stage Peltier element 31. The middle-stage Peltier element 32 absorbs heat from the upper-stage thermal conductor 34, and discharges the absorbed heat to the lower-stage thermal conductor 35 together with heat generated by the drive of the middle-stage Peltier element 32.

[0042] The lower-stage Peltier element 33 absorbs heat from the middle-stage thermal conductor 35 (i.e., absorbs the amount of heat emitted from the upper-stage and middle-stage Peltier elements 31, 32) in order to maintain the temperature of the heat exhaust side of the middle-stage Peltier element 32 at a reference value, and exhausts the absorbed heat to the fins together with heat generated by driving the lower-stage Peltier element 33. In other words, the lower-stage Peltier element 33 stabilizes the temperature of the heat exhaust side of the upper-stage and middle-stage Peltier elements 31, 32. This allows the upper-stage and middle-stage Peltier elements 31, 32 to cancel the amount of heat absorbed from the temperature control target, the amount of heat generated by themselves, and the temperature and temperature changes of the external environment.

[0043] As an example, the set value, which is the target value for the inside temperature, may be set at a point between plus 40 and minus 40°C, with an error of ±2°C being allowed. The target value of the upper-stage Peltier element 31 (hereinafter referred to as the upper-stage target value) is set based on the set value (see FIG. 6). For example, the upper-stage target value may be set a predetermined temperature (e.g., 0°C to 5°C) lower (or higher) than the set value.

[0044] The upper stage target value may be corrected based on the temperature difference between the measured value Tcp1 of the heat absorption side of the upper stage Peltier element 31, i.e., the temperature of the thermal conductor 36, and the measured value Tx of the inside temperature. For example, the upper stage target value is corrected by adding or subtracting the difference between the inside temperature and the set temperature to or from the target value.

[0045] A target value (hereinafter referred to as middle stage target value) that is synchronized with the upper stage target value with a certain temperature difference is set for the middle stage Peltier element 32. The set temperature difference is, for example, 5°C to 30°C.

[0046] The reference value of the lower Peltier element 33 is set separately from the set value, the upper target value, and the middle target value. From the viewpoint of preventing condensation, the reference value is set to, for example, +5°C, and an error of ±1°C may be allowed. The lower Peltier element 33 is controlled so that the measured value Tcp3 of the temperature of the thermal conductor 35 on the heat absorption side approaches the reference value.

[0047] The reference value may be corrected based on the measured value of the outside air temperature Ta. For example, the reference value is corrected by multiplying the reference value by a certain coefficient based on the outside air temperature.

[0048] 2-2.Heat conductor As described above, the thermal conductors 34, 35 are disposed between the upper, middle, and lower Peltier elements 31-33. The thermal conductors 34, 35 are plates made of a metal material such as an aluminum alloy, and the thermal conductors 34, 35 are respectively equipped with temperature sensors 42, 44. The thermal conductors 34, 35 space the upper, middle, and lower Peltier elements 31-33 at a certain distance, thereby suppressing the return of heat due to radiant heat or the like, which may occur when the Peltier elements are driven in a state where they are directly stacked, and provide a sufficient temperature difference between the upper, middle, and lower Peltier elements 31-33. In other words, the thermal conductors 34, 35 have the effect of suppressing the reverse flow of heat and rectifying the heat in a desired direction.

[0049] However, if the thickness of the thermal conductors 34, 35 is too large, the volume (i.e., heat capacity) of the thermal conductors 34, 35 will be large, and the energy required to cool the thermal conductors 34, 35 will increase. Also, the time required to reach the upper and lower target values ​​will be longer, and the response speed of the Peltier element to temperature control will decrease. Taking into consideration the temperature stability after reaching the upper and lower target values, the thickness of the thermal conductors 34, 35 is preferably 3 to 8 mm, and more preferably 4 to 6 mm.

[0050] 2-3. Control method For example, a control method based on PID control is used for the temperature control of the upper Peltier element 31. However, in the PID control, since the temperature is gradually adjusted before reaching the upper target value in order to suppress overshoot, it takes time to reach the upper target value.

[0051] Therefore, in this embodiment, when the difference between the measured value Tx of the inside temperature and the measured value Tcp1 of the temperature of the thermal conductor 36 is within a predetermined range (e.g., -5°C to +5°C), the upper target value is corrected to, for example, "upper target value -4°C" to shorten the time to reach the upper target value. When the temperature difference becomes even smaller, for example, to about -3°C to +3°C, the correction of the upper target value is terminated and the original target value is restored. This makes it possible to quickly reach the upper target value while suppressing overshooting.

[0052] The temperature control of the middle stage Peltier element 32 is performed in synchronization with the temperature control of the upper stage Peltier element 31. However, the middle stage target value is set to be lower (or higher) by a certain constant temperature than the upper stage target value.

[0053] A control method based on PID control is used for the temperature control of the lower Peltier element 33, and control is performed with a reference value as a target. However, in order to suppress the influence of an increase in heat inflow due to an increase in the load on the heat absorption side and a change in the external environment temperature (for example, a sudden rise or fall in the outside air temperature), the reference value is corrected based on the outside air temperature to suppress deviation of the temperature of the thermal conductor 44 from the reference value. If the measured outside air temperature Ta falls below the reference value, the polarity of the power supply of the lower Peltier element 33 is switched, and the surface of the middle side of the lower Peltier element 33 is heated.

[0054] In this way, the lower Peltier element 33 is controlled so as to provide a stable temperature on its heat absorption side (middle side) in response to a wide range of temperature environments on the heat exhaust side (heat dissipation fin 37 side). This enables precise temperature control based on a constant temperature for the upper and middle Peltier elements 31 and 32.

[0055] 2-4. Determining the number of driven middle and lower Peltier elements 32, 33 As described above, each of the middle and lower Peltier elements 32, 33 includes a plurality of Peltier modules. In this embodiment, the middle Peltier element 33 includes two Peltier modules, and the lower Peltier element 34 includes four Peltier modules (see FIG. 5).

[0056] From the viewpoint of suppressing the power consumption of the middle and lower Peltier elements 32, 33, the number of Peltier modules to be driven in the middle and lower stages is changed based on the temperature difference between the heat absorption side and the heat exhaust side of the middle and lower Peltier elements 32, 33 (for example, the difference between the measured values ​​Tcp2 and Tcp3, and the difference between the measured values ​​Tcp3 and Th) (see FIG. 7). In other words, the amount of power supplied to the middle and lower Peltier elements 32, 33, i.e., the driving power, derived from such a temperature difference is evaluated as a percentage of the maximum power (maximum set output) that can be supplied to the middle and lower Peltier elements 32, 33 (i.e., how much margin there is), and the number of Peltier modules to be driven in the middle and lower stages is determined according to the evaluation result.

[0057] As shown in an example in FIG. 8 to FIG. 10, the numbers of Peltier modules to be driven in the middle and lower stages are determined as follows according to the level of the load, such as minimum load, medium load, and maximum load. -Number of Peltier modules driven in the middle row temperature difference Number of drives Over 35℃ 1 Below 35℃ 2 - Number of Peltier modules driven in the lower row temperature difference Number of drives Over 45℃ 1 Over 40℃ 2 Over 35℃ 3 Below 35℃ 4

[0058] In this regard, the control method of the temperature adjustment unit 30 by uniformly increasing or decreasing the driving power of the middle and lower Peltier elements 32, 33 cannot be expected to sufficiently reduce the driving power, given that a certain amount of heat is generated in the Peltier module during low-power operation.

[0059] 2-5. Power saving mode at startup For example, consider a situation immediately after power is turned on to the temperature control device 1 placed indoors. The storage container 20 is not cooled (or heated), and the temperature inside the container is the same as the room temperature. If temperature control is started in this state, the Peltier elements of each stage of the temperature control device may start operating at full power.

[0060] Generally, a Peltier element does not exhibit sufficient cooling capacity when full power is applied, and tends to enter a driving state in which a relatively large amount of heat is generated. In other words, the energy efficiency of the Peltier element in this state is poor.

[0061] Therefore, in this embodiment, the power input to the temperature adjustment unit 30 is limited to a certain percentage of the maximum power that can be supplied for a certain period of time from the output of the start time limit signal (see FIG. 11). Operation in this state suppresses the power consumption of the temperature adjustment unit 30. As an example, the duration of this operation mode is one minute, but is not limited to this. Furthermore, the upper limit of the input power is, for example, 60% to 85% of the maximum power, but is not limited to this.

[0062] 3. Operation of Temperature Control Device 1 The operation of the temperature adjustment apparatus 1 will be described, particularly from the perspective of temperature management of the temperature adjustment unit 30. Such temperature management is mainly performed by the control device 50.

[0063] In the following example, the temperature management of the upper and middle Peltier elements 31, 32 is performed under one control flow, and the temperature management of the lower Peltier element 33 is performed under a different control flow, but the present invention is not limited to this.

[0064] 3-1. Temperature control of the upper and middle shelves The temperature management of the upper and middle Peltier elements 31, 32 will be described with reference to FIGS.

[0065] When the power is turned on, the temperature management starts for the upper and middle Peltier elements 31, 32. At this time, a start time limit signal is output.

[0066] In step S11, it is determined whether a predetermined time (for example, one minute) has elapsed since power-on or output of a start time limit signal. If the predetermined time has not elapsed, in step S12, the upper limit of the drive output of the upper and middle Peltier elements 31, 32 is limited to a predetermined percentage of the maximum power that can be supplied, and if not, the process proceeds to the next step S13.

[0067] In step S13, the set value is set automatically or based on a user input, and the upper stage target value is calculated based on the set value. The upper stage target value is set, for example, to a predetermined temperature lower (or higher) than the set value. Then, in step S14, the upper stage Peltier element 31 is controlled, for example, by PID control, aiming for the upper stage target value.

[0068] In step S15, a middle stage target value is set according to the upper stage target value, which is set to be lower than the upper stage target value by a predetermined value.

[0069] Next, in step S16, it is determined whether the heating mode is enabled. The determination condition is, for example, whether the measured value Ta of the outside air temperature is equal to or lower than a set value. If the outside air temperature is equal to or lower than the set value, it is necessary to increase the temperature inside the storage container 20.

[0070] If it is determined that the heating mode should be selected, power supply to the middle-stage Peltier element 32 is stopped in step S17, the output of the upper-stage Peltier element 31 is limited in step S18, and further, the polarity of the voltage applied to the upper-stage Peltier element 31 is reversed in step S19. As a result, the upper-stage Peltier element 31 heats the storage container 20. Then, the procedure proceeds to step S23.

[0071] Alternatively, if it is determined in step S16 that the heating mode should not be selected, the temperature difference (Tcp2-Tcp3) between both sides of the middle-stage Peltier element 32 is acquired in step S20. If this temperature difference is less than a predetermined value (e.g., 35°C), both of the two Peltier modules constituting the middle-stage Peltier element 32 are operated in step S21. Alternatively, if the temperature difference is equal to or greater than a predetermined value (e.g., 35°C), in order to reduce power consumption, only one of the two Peltier modules in the middle-stage Peltier element 32 is operated in step S22. Note that step S21 may be set as a default.

[0072] Next, in step S23, a stability determination is made for the upper stage target value.

[0073] By default, the process proceeds to step S24, where it is determined whether the measured value Tcp1 of the temperature on the heat absorption side of the upper Peltier element 31 is within a predetermined allowable range (for example, ±2°C) of the upper target value. If it is determined that the measured value Tcp1 is within the allowable range of the upper target value, the process proceeds to step S25, where the time during which the measured value Tcp1 remains within the allowable range of the upper target value, i.e., the duration, is measured.

[0074] Then, in step S26, it is determined whether the duration meets a predetermined specified value (for example, 20 minutes). If it is determined that the duration meets the specified value, it is evaluated in step S27 that the upper target value has been achieved. If not, the measurement of the duration is reset in step S28.

[0075] If it is determined in step S24 that the measurement value Tcp1 is not within the allowable range of the upper target value, the process proceeds to step S35, which will be described later.

[0076] Alternatively, if it is determined in step S23 that the upper target value is not stable, the process proceeds to step S29, where the upper target value is corrected.

[0077] Next, in step S30, it is determined whether the measured value Tx of the internal temperature of the storage container 20 is within an allowable range of the set value (e.g., ±2°C). If it is determined that the measured value Tx is within the allowable range of the set value, the duration of that state is measured in step S31.

[0078] Then, in step S32, it is determined whether the measured duration meets a predetermined specified value (for example, 20 minutes). If it is determined that the duration meets the specified value, it is determined in step S33 that the temperature inside the refrigerator is stable, and if not, the measurement of the duration is reset in step S34. Then, the process proceeds to step S35.

[0079] Alternatively, if it is determined in step S30 that the measurement value Tx is not within the allowable range of the set value, the process proceeds to step S35 without passing through steps S31 to S34.

[0080] In step S35, it is determined whether the measured temperature Tcp1 of the heat absorption side of the upper Peltier element 31 and the measured temperature Tx inside the container are stable. If it is determined that the temperature of the upper Peltier element 31 and the inside temperature are stable, it is determined in step S36 that the inside of the storage container 20 has reached the set value, and if not, it is determined in step S37 that the inside of the storage container 20 has not yet reached the set value, and the series of procedures is terminated. The above process is repeatedly executed at a predetermined cycle (for example, every 0.5 seconds).

[0081] 3-2. Temperature control of the lower level With reference to FIG. 14, the temperature management of the lower Peltier element 33 will be described. When the power is turned on, the temperature management starts for the lower-stage Peltier element 33. The temperature control of the lower-stage Peltier element 33 starts in synchronization with the temperature control of the other stages.

[0082] In step S51, it is determined whether a predetermined time (for example, one minute) has elapsed since power-on or output of a start time limit signal. If the predetermined time has not elapsed, in step S52, the upper limit of the drive output is limited to a predetermined ratio of the maximum power that can be supplied to the lower-stage Peltier element 33, and the process proceeds to the next step S53.

[0083] In step S53, a reference value, which is a temperature target of the lower Peltier element 33, is corrected based on the measured outside air temperature Ta. The reference value is preset to a temperature higher or lower than the upper and middle target values. Then, in step S54, the lower Peltier element 33 is controlled, for example, by PID control, aiming for the reference value.

[0084] Next, in step S55, it is determined whether or not the heating mode is enabled. The determination condition is, for example, whether the measured outside air temperature Ta is equal to or lower than a reference value (e.g., 5°C). Since the main role of the lower Peltier element 33 is to maintain the temperature of the heat exhaust side of the upper and middle Peltier elements 31, 32 constant, when the outside air temperature is equal to or lower than the reference value, it is necessary to increase the temperature of the heat exhaust side of the upper and middle Peltier elements 31, 32.

[0085] If it is determined that the heating mode should be selected, control of the lower Peltier element 33 is stopped in step S56, and the process proceeds to step S62. Otherwise, in step S57, the difference (Th-Tcp3) between the measured temperatures on both sides of the lower Peltier element 33 is obtained, and the process branches to steps S58 to S61 depending on the temperature difference.

[0086] That is, if the temperature difference is, for example, less than 35° C., all four Peltier modules in the lower-stage Peltier element 33 are operated in step S58 (see FIG. 10). This step is the process at maximum load. Alternatively, if the temperature difference is, for example, 35° C. or more, in step S59, three Peltier modules are operated and the remaining one is not operated. Alternatively, if the temperature difference is, for example, 40° C. or more, in step S60, two Peltier modules are operated and the remaining two are not operated (see FIG. 9). These steps are the processing during medium load. Alternatively, if the temperature difference is, for example, 45° C. or more, in step S61, only one Peltier module is operated and the remaining three are not operated (see FIG. 8). This step is the process at the time of minimum load.

[0087] Next, in step S62, it is determined whether the reference value of the lower Peltier element 33 is within an allowable range (for example, ±0.5° C.). If it is determined that the reference value is within this allowable range, in step S63, the duration of this state is measured.

[0088] Then, in step S64, it is determined whether the duration meets a predetermined specified value (for example, 20 minutes). If it is determined that the duration meets the specified value, it is evaluated that the lower Peltier element 33 is stable in step S65, and if not, the duration measurement is reset in step S66. Then, the series of processes is terminated.

[0089] Alternatively, if it is determined in step S62 that the lower Peltier element 33 is not within the allowable range of the reference value, the series of processes ends without going through steps S63 to S66. The above process is repeatedly executed at a predetermined cycle (for example, every second).

[0090] As a result of the above processing, it is possible to suppress fluctuations in the inside temperature to a small extent when the outside air temperature, which is higher than the inside temperature, rises further suddenly or drops more suddenly than the inside temperature, or when the outside air temperature, which is lower than the inside temperature, rises more suddenly than the inside temperature, as shown in the example of Figure 15. In the example of Figure 15, even though the outside air temperature changes from +15°C to -28°C, the inside temperature is kept within ±0.2°C of the target value of -16°C.

[0091] Such a change in outside air temperature mimics a sudden change in environmental temperature that occurs when moving from indoors to outdoors or from outdoors to indoors. Therefore, the temperature adjustment device 1 can quickly stabilize the temperature inside the storage unit by minimizing the effects of a sudden change in environmental temperature that occurs when moving from indoors to outdoors or from outdoors to indoors.

[0092] 4. Effects of this embodiment In this embodiment, the temperature adjustment unit 30 is configured with multiple stages of Peltier elements, and different roles are assigned to each stage. In other words, the upper and middle stage Peltier elements 31 and 32 are made to follow their respective target values, and the lower stage Peltier element 33 is made to follow a reference value. Therefore, the temperature on the heat exhaust side of the upper and middle stage Peltier elements 31 and 32 is stabilized, and as a result, the difference between the inside temperature and the upper and middle stage target values ​​is stabilized. This prevents the temperature on the heat exhaust side of the upper and middle stage Peltier elements 31 and 32 from becoming too high, and a sufficient amount of heat absorption can be secured, making it possible to drive the temperature adjustment unit 30 with high cooling capacity and high efficiency.

[0093] Moreover, by adjusting the number of driven Peltier modules included in the middle and lower stages according to the power supplied to the middle and lower stages, the drive power of the temperature adjustment unit 30 can be reduced.

[0094] By interposing the heat transfer bodies 34, 35 having a predetermined thickness between the Peltier elements 31-33 of each stage, it is possible to suppress heat return from the heat generating side to the heat absorbing side in the upper and lower Peltier elements 31, 32. Therefore, it is possible to efficiently utilize the Peltier elements 31-33 of each stage.

[0095] Furthermore, by limiting the amount of power supplied to the temperature adjustment unit 30 when the temperature adjustment device 1 is turned on, operation at full power, which is relatively inefficient, is avoided, and as a result, power consumption is suppressed.

[0096] In this way, power saving is ensured by using the temperature adjustment unit 30 under relatively efficient operating conditions. Therefore, the temperature adjustment device 1 can use the built-in battery for a longer period of time and can be transported over relatively long distances.

[0097] Furthermore, by stacking the Peltier elements in multiple stages, the voltage required to drive the temperature adjustment unit 30 can be reduced, which allows the built-in battery to be made smaller, thereby realizing a reduction in the weight of the temperature adjustment device 1. This improves portability.

[0098] Furthermore, since the temperature adjustment unit 30 can be configured with an inexpensive general-purpose module instead of a high-performance but expensive dedicated module, the manufacturing cost can be reduced.

[0099] 5. Modifications 1 to 3 of this embodiment Temperature adjustment devices according to Modifications 1 to 3 of this embodiment will be described with reference to Figures 16 to 18. The temperature adjustment devices according to these modifications differ from the temperature adjustment device 1 according to this embodiment mainly in the temperature adjustment units 130, 230, and 330. Therefore, Modifications 1 to 3 will be described below, focusing on the temperature adjustment units 130, 230, and 330.

[0100] 5-1. Variation 1 In the first modification, the temperature adjustment unit 130 includes upper, middle and lower Peltier elements 131, 132 and 133. Thermal conductors 134, 135 are interposed between the upper Peltier element 131 and the middle Peltier element 132, and between the middle Peltier element 132 and the lower Peltier element 133, respectively, to thermally connect the Peltier elements of each stage. A thermal conductor 136 is also disposed on the heat absorption side of the upper Peltier element 131, to thermally connect a storage container (not shown) and the upper Peltier element 131. A heat dissipation fin 137 is attached to the heat exhaust side of the lower Peltier element 133.

[0101] The numbers of Peltier modules constituting the upper, middle and lower Peltier elements 131, 132 and 133 are 1, 1 and 2, respectively. By increasing the number of modules in the lower stage compared to the number of modules in the upper and middle stages, the exhaust heat from the upper and middle stage Peltier elements 131 and 132 can be sufficiently absorbed by the lower stage Peltier element 133. Therefore, regardless of changes in the outside air temperature, the temperature on the heat exhaust side of the upper and middle stage Peltier elements 131 and 132 can be stabilized, and an efficient temperature adjustment unit 130 can be constructed.

[0102] 5-2. Variation 2 In the second modification, the temperature adjustment unit 230 includes upper, middle and lower Peltier elements 231, 232 and 233. Thermal conductors 234, 235 are interposed between the upper Peltier element 231 and the middle Peltier element 232, and between the middle Peltier element 232 and the lower Peltier element 233, respectively, to thermally connect the Peltier elements of each stage. A thermal conductor 236 is also disposed on the heat absorption side of the upper Peltier element 231, to thermally connect a storage container (not shown) and the upper Peltier element 231. A heat dissipation fin 237 is attached to the heat exhaust side of the lower Peltier element 233.

[0103] The numbers of Peltier modules constituting the upper, middle and lower Peltier elements 231, 232 and 233 are 2, 2 and 4, respectively. By increasing the number of modules in the lower stage compared to the number of modules in the upper and middle stages, the exhaust heat from the upper and middle stage Peltier elements 231, 232 can be sufficiently absorbed by the lower stage Peltier element 233. Therefore, regardless of changes in the outside air temperature, the temperature on the exhaust side of the upper and middle stage Peltier elements 231, 232 can be stabilized, and an efficient temperature adjustment unit 230 can be constructed.

[0104] The temperature adjustment unit 230 in the second modification includes twice as many modules per stage as the temperature adjustment unit 130 in the first modification. Therefore, the temperature adjustment unit 230 in the second modification has higher cooling performance than the temperature adjustment unit 130 in the first modification.

[0105] 5-3. Variation 3 In the third modification, the temperature adjustment unit 330 includes upper, middle and lower Peltier elements 331, 332 and 333. Thermal conductors 334, 335 are interposed between the upper Peltier element 331 and the middle Peltier element 332, and between the middle Peltier element 332 and the lower Peltier element 333, respectively, to thermally connect the Peltier elements of each stage. A thermal conductor 336 is also disposed on the heat absorption side of the upper Peltier element 331, to thermally connect a container (not shown) and the upper Peltier element 331. A heat dissipation fin 337 is attached to the heat exhaust side of the lower Peltier element 333.

[0106] The numbers of Peltier modules constituting the upper, middle and lower Peltier elements 331, 332 and 333 are 1, 1 and 4, respectively. By increasing the number of modules in the lower stage compared to the number of modules in the upper and middle stages, the exhaust heat from the upper and middle stage Peltier elements 331 and 332 can be sufficiently absorbed by the lower stage Peltier element 333. Therefore, regardless of changes in the outside air temperature, the temperature on the heat exhaust side of the upper and middle stage Peltier elements 331 and 332 can be stabilized, and an efficient temperature adjustment unit 330 can be constructed.

[0107] The temperature adjustment unit 330 in Modification 3 has twice as many modules in the lower tier as in the upper and middle tiers compared to the temperature adjustment units 130, 230 in Modifications 1 and 2. Therefore, it is considered that the temperature adjustment unit 330 in Modification 3 is less susceptible to temperature changes in the external environment and is more stable than the temperature adjustment units 130, 230 in Modifications 1 and 2.

[0108] Representative embodiments and modifications of the present invention have been described above, but the present invention is not limited to these, and various design modifications are possible. It goes without saying that such design modifications (modifications) also fall within the technical scope of the present invention.

[0109] For example, the temperature adjustment unit is not limited to a configuration consisting of upper, middle and lower Peltier elements, but may be composed of upper and lower Peltier elements, or may be composed of four or more stages of Peltier elements.

[0110] Furthermore, each of the upper, middle and lower Peltier elements 31 to 33 may be formed from one Peltier module. [Explanation of symbols]

[0111] 1 Temperature control device 10. Chassis 20 Storage Container 30,130,230,330 Temperature control unit 31,131,231,331 Upper Peltier element 32,132,232,332 Middle Peltier element 33,133,233,333 Lower Peltier element 34~36, 134~136, 234~236, 334~336 Thermal conductor 37,137,237,337 Heat dissipation fin 41~46 Temperature sensor 50 Control Device

Claims

1. A housing and A storage container that is housed in the housing and that houses a temperature control target and includes a heat conductive portion; a temperature adjustment unit including an upper Peltier element thermally connected to the storage container at a first surface, a lower Peltier element thermally connected to a second surface of the upper Peltier element and the first surface, and a heat dissipation fin thermally connected to the second surface of the lower Peltier element; A control device for controlling the temperature adjustment unit; a temperature sensor for measuring the temperature of each of the first surface side of the upper Peltier element and the first surface side of the lower Peltier element, The control device a first control unit that controls the upper Peltier element so that a measurement value indicating a temperature on a first surface side of the upper Peltier element becomes a set value; a second control unit that controls the lower Peltier element so that a measurement value indicating a temperature of a first surface of the lower Peltier element becomes a predetermined reference value that is set separately from the set value; A temperature control device characterized by the above.

2. The temperature sensor further measures an internal temperature of the storage container, the first control unit corrects the set value according to a difference between a measured value indicating an internal temperature of the storage container and a temperature of a first surface side of the upper Peltier element, and controls the upper Peltier element using the corrected set value; The temperature control device according to claim 1 .

3. The temperature sensor further measures an outside air temperature; the second control unit corrects the reference value in response to the measured value of the outside air temperature, and controls the lower-stage Peltier element using the corrected reference value; The temperature control device according to claim 1 or 2,

4. the first control unit and the second control unit limit the drive power of the upper Peltier element and the lower Peltier element to a predetermined percentage of a maximum set output within a predetermined period from the start of drive of the temperature adjustment unit; The temperature control device according to any one of claims 1 to 3,

5. The control device selects a Peltier element to be driven from among the plurality of Peltier elements according to a drive output for one or more stages having a plurality of Peltier elements; The temperature control device according to any one of claims 1 to 3,

6. the temperature adjustment unit further includes a thermal conductor interposed between the upper Peltier element and the lower Peltier element; The temperature control device according to claim 5 .

7. The temperature adjustment unit further includes one or more middle-stage Peltier elements thermally connected to the upper-stage Peltier element on a first surface and the lower-stage Peltier element on a second surface, the temperature sensor further measures a temperature of a first surface of the middle stage Peltier element; the first control unit controls the middle-stage Peltier element so that a measured value indicating a temperature of a first surface of the middle-stage Peltier element reaches a predetermined temperature difference from the set value; The temperature control device according to any one of claims 1 to 6,

8. 8. The temperature control device according to claim 1, wherein the temperature control device has a weight of 20 kg or less when driven by a battery.

9. further comprising a temperature logger for recording the measurements of the temperature sensor; The temperature control device according to any one of claims 1 to 8,

10. Further comprising wireless or wired communication means for communicating with an external device; The temperature control device according to any one of claims 1 to 9,

11. A housing and A storage container that is housed in the housing, stores a temperature control target, and includes a heat conductive portion; a temperature adjustment unit including an upper Peltier element thermally connected to the storage container at a first surface, a lower Peltier element thermally connected to a second surface of the upper Peltier element and the first surface, and a heat dissipation fin thermally connected to the second surface of the lower Peltier element; a temperature sensor for measuring the temperatures of the first surface side of the upper Peltier element and the first surface side of the lower Peltier element; a step of controlling the upper Peltier element so that a measurement value indicating a temperature on a first surface side of the upper Peltier element becomes a set value; a step of controlling the lower Peltier element so that a measured value indicating a temperature of a first surface of the lower Peltier element becomes a predetermined reference value that is set separately from the set value; A temperature adjustment device control method comprising:

Images