Cooling device and its operation method

Abstract

A cooling device for cooling the cooling chamber of a refrigerated container includes: a turbine that expands air drawn in from the cooling chamber; and a control device that controls the operation of the turbine. The control device includes a start-up unit that, when the cooling device is started, causes the turbine to operate at a first speed until the turbine inlet temperature drops below a predetermined inlet side temperature. When the turbine inlet temperature is below the predetermined inlet side temperature, the start-up unit causes the turbine to operate at a second speed greater than the first speed.

Description

Technical Field

[0001] This disclosure relates to a cooling device for cooling the cooling compartment of a refrigerated container and a method for operating the cooling device.

[0002] This application claims priority based on Japanese Patent Application No. 2023-200691, filed with the Japan Patent Office on November 28, 2023, the contents of which are incorporated herein by reference. Background Technology

[0003] For example, Patent Document 1 discloses a cooling device that uses an air refrigerant cycle (a method of cooling air drawn in from a cooling chamber and then expelling the cooled air back into the cooling chamber). Such a cooling device includes a turbine that expands the air drawn in from the cooling chamber for cooling.

[0004] Existing technical documents

[0005] Patent Document 1: Japanese Patent No. 3891668 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] When the cooling device is started, the moisture in the air drawn in from the cooling chamber may freeze inside the turbine when the turbine speed is increased sharply. When ice forms inside the turbine, the airflow inside the turbine decreases, resulting in a reduction in the performance of the cooling device. In the cooling device described in Patent Document 1, since an ice condenser is provided on the air outlet side of the expander (turbine), ice may form inside the turbine when the cooling device is started. Moreover, unlike cold storage facilities with large-capacity cooling chambers (such as large cold storage warehouses), the size of the cooling device installed in a refrigerated container is limited, so it is desirable to prevent the cooling device from becoming too large.

[0008] This disclosure was made in view of the above-mentioned problems, and its object is to provide a cooling device and a method for operating the cooling device that can suppress the reduction in performance caused by icing in the turbine during startup.

[0009] Methods for solving problems

[0010] To achieve the above objectives, the cooling device of the present invention is used to cool the cooling chamber of a refrigerated container. The cooling device includes: a turbine that expands air drawn in from the cooling chamber; and a control device that controls the operation of the turbine. The control device includes a start-up operation unit. When the cooling device is started, the start-up operation unit causes the turbine to operate at a first speed until the inlet temperature of the turbine drops below a predetermined inlet side temperature. When the inlet temperature of the turbine is below the predetermined inlet side temperature, the start-up operation unit causes the turbine to operate at a second speed greater than the first speed.

[0011] To achieve the above objectives, the cooling device of the present invention is used to cool the cooling chamber of a refrigerated container. The cooling device includes: a turbine that expands air drawn in from the cooling chamber; and a control device that controls the operation of the turbine. The control device includes a start-up unit that, when the cooling device is started, causes the turbine to operate at a first speed until the outlet temperature of the turbine drops below a predetermined outlet temperature. When the outlet temperature of the turbine is below the predetermined outlet temperature, the start-up unit causes the turbine to operate at a second speed greater than the first speed.

[0012] To achieve the above objectives, the cooling device of the present invention is used to cool the cooling chamber of a refrigerated container, and the cooling device comprises: A turbine expands the air drawn in from the cooling chamber; and a control device controls the operation of the turbine, the control device including a start-up unit that, when the cooling device is started, causes the turbine to operate at a first speed until the outlet temperature of the turbine drops below a predetermined outlet temperature; when the outlet temperature of the turbine is below the predetermined outlet temperature, the start-up unit causes the turbine to operate at a second speed greater than the first speed, and causes the turbine to operate at the second speed until the inlet temperature of the turbine drops below a predetermined inlet temperature; when the inlet temperature of the turbine is below the predetermined inlet temperature, the start-up unit causes the turbine to operate at a third speed greater than the second speed.

[0013] To achieve the above objectives, the cooling device operation method disclosed herein is used to cool the cooling chamber of a refrigerated container. The cooling device includes a turbine that expands air drawn in from the cooling chamber. The cooling device operation method includes the following steps: when the cooling device is started, the turbine is operated at a first speed until the inlet temperature of the turbine drops below a predetermined inlet side temperature; when the inlet temperature of the turbine is below the predetermined inlet side temperature, the turbine is operated at a second speed greater than the first speed.

[0014] To achieve the above objectives, the cooling device operation method disclosed herein is used to cool the cooling chamber of a refrigerated container. The cooling device includes a turbine that expands air drawn in from the cooling chamber. The operation method of the cooling device includes the following steps: when the cooling device is started, the turbine is operated at a first speed until the outlet temperature of the turbine drops to less than a predetermined outlet side temperature; when the outlet temperature of the turbine is less than the predetermined outlet side temperature, the turbine is operated at a second speed greater than the first speed.

[0015] To achieve the above objectives, the cooling device operation method disclosed herein is used to cool the cooling chamber of a refrigerated container. The cooling device includes a turbine that expands air drawn in from the cooling chamber. The operation method of the cooling device includes the following steps: when the cooling device is started, the turbine is operated at a first speed until the outlet temperature of the turbine drops below a predetermined outlet temperature; when the outlet temperature of the turbine is below the predetermined outlet temperature, the turbine is operated at a second speed greater than the first speed, and the turbine is operated at the second speed until the inlet temperature of the turbine drops below a predetermined inlet temperature; when the inlet temperature of the turbine is below the predetermined inlet temperature, the turbine is operated at a third speed greater than the second speed.

[0016] Invention Effects

[0017] According to the cooling device and its operation method disclosed herein, it is possible to suppress large-scale operation and to suppress performance degradation caused by icing inside the turbine during startup. Attached Figure Description

[0018] Figure 1 This is a diagram that roughly illustrates an example of the structure of a refrigerated container.

[0019] Figure 2 This is a diagram that schematically illustrates the structure of the cooling device according to the first embodiment.

[0020] Figure 3 This is a schematic functional block diagram of the control device according to the first embodiment.

[0021] Figure 4 This is a diagram that schematically illustrates the structure of the cooling device according to the second embodiment.

[0022] Figure 5 This is a schematic functional block diagram of the control device according to the second embodiment.

[0023] Figure 6This is a diagram that schematically illustrates the structure of the cooling device according to the third embodiment.

[0024] Figure 7 This is a schematic functional block diagram of the control device according to the third embodiment.

[0025] Figure 8 This is a diagram that schematically illustrates the structure of a turbine according to one embodiment.

[0026] Figure 9 This is a diagram used to illustrate the "hydrophobic" property in this disclosure.

[0027] Figure 10 This is an enlarged perspective view of a portion of the vortex flow path forming section according to one embodiment.

[0028] Figure 11 This is an enlarged perspective view of a portion of the nozzle flow path forming section according to one embodiment.

[0029] Figure 12 This is a diagram that schematically illustrates the internal structure of a turbine according to one embodiment.

[0030] Figure 13 This is a flowchart illustrating the operation method of a cooling device according to one embodiment.

[0031] Figure 14 This is a flowchart illustrating the operation method of a cooling device according to another embodiment.

[0032] Figure 15 This is a flowchart illustrating the operation method of a cooling device according to another embodiment. Detailed Implementation

[0033] Hereinafter, a cooling device and a method for operating the cooling device according to an embodiment of the present disclosure will be described based on the accompanying drawings. This embodiment represents one aspect of the present disclosure and does not limit the present disclosure; it can be modified arbitrarily within the scope of the technical concept of the present disclosure.

[0034] The cooling device disclosed herein cools the cooling chamber of a refrigerated container. This cooling device utilizes a method of cooling air drawn from the cooling chamber and then returning the cooled air to the cooling chamber (air-refrigerant circulation).

[0035] Figure 1 This is a diagram that roughly illustrates an example of the structure of a refrigerated container 100. (See diagram for example.) Figure 1 As illustrated, the refrigerated container 100 includes a main body 102 and the cooling device 1 of this disclosure.

[0036] The main body 102 has a rectangular cylindrical shape and includes an upper wall, a lower wall, a left wall, a right wall, and a rear wall, with an open front surface. A cooling device 1 is embedded in the front surface of the main body 102. The interior of the main body 102 is divided into a cooling chamber 101 by being surrounded by the upper wall, lower wall, left wall, right wall, rear wall, and cooling device 1. Although not shown, the cooling chamber 101 may also have an openable and closable door in at least one of the left wall, right wall, and rear wall to allow an operator to enter and exit the cooling chamber 101. In several embodiments, the main body 102 includes a front wall in which the cooling device 1 is embedded.

[0037] The cooling device 1 uses air refrigerant circulation as described above, and uses turbine 2 (expansion turbine) to cool the air drawn in from the cooling chamber 101 (hereinafter referred to as suction air A2) to generate cooling air A1, and then sends the cooling air A1 out of the cooling chamber 101. Figure 1 In the illustrated embodiment, the cooling device 1 is configured to maintain the temperature of the cooling chamber 101 within a range of -40 degrees Celsius or higher and less than 20 degrees Celsius. That is, Figure 1 The illustrated refrigerated container 100 is a cryogenic container (so-called a refrigerated container). In several embodiments, the refrigerated container 100 is an ultra-low temperature container or a cryogenic container capable of maintaining the internal temperature of the cooling chamber 101 below -40 degrees Celsius.

[0038] Cooling device

[0039] (structure)

[0040] The structure of the cooling device 1A(1) of the first embodiment will be described. Figure 2 This is a diagram that schematically illustrates the structure of the cooling device 1A according to the first embodiment. (As shown...) Figure 2 As shown, the cooling device 1A includes a turbine 2 and a control device 4. Figure 2 In the illustrated configuration, the cooling device 1A further includes: an air line 6, a heat exchanger 8, a compressor 10, and an air cooler 12.

[0041] The air duct 6 is constructed, for example, by piping or conduit, and internally forms a flow path that draws in suction air A2 from the cooling chamber 101 and delivers cooled air A1, after cooling the suction air A2, to the cooling chamber 101. The air duct 6 is equipped with a heat exchanger 8, a compressor 10, an air cooler 12, and a turbine 2. The suction air A2 flows in the air duct 6 in the following order from the upstream side: heat exchanger 8, compressor 10, air cooler 12, heat exchanger 8, and turbine 2.

[0042] The heat exchanger 8 uses the suction air A2, which has just been drawn in from the cooling chamber 101 via a heat transfer wall (not shown), as a refrigerant to cool the suction air A2 compressed by the compressor 10. The suction air A2 cooled by the heat exchanger 8 is then supplied to the turbine 2. The suction air A2 used as a refrigerant is then supplied to the compressor 10 at room temperature (15°C to 30°C).

[0043] Compressor 10 compresses the suction air A2, which has reached room temperature after passing through heat exchanger 8, thereby increasing the temperature and pressure of the suction air A2. Figure 2 In the illustrated configuration, the cooling device 1 also includes an electric motor 14 and a pair of drive shafts 15a and 15b extending coaxially from the electric motor 14. The compressor 10 is connected to and driven by the electric motor 14 via a drive shaft 15a. Additionally, the compressor 10 receives power generated by the turbine 2 via the pair of drive shafts 15a and 15b, enabling the turbine 2's power to be utilized as an auxiliary force for driving.

[0044] Air cooler 12 cools (pre-cools) the suction air A2 that has been heated and pressurized by compressor 10. Air cooler 12 is, for example, a finned tube heat exchanger, including a cooling water flow path for cooling water. Air cooler 12 exchanges heat between the heated and pressurized suction air A2 and the cooling water, cooling the suction air A2 to room temperature. Furthermore, air cooler 12 can have any structure as long as it can cool the suction air A2 to room temperature. For example, air cooler 12 can also cool the heated and pressurized suction air A2 to room temperature using cooling air instead of cooling water.

[0045] The suction air A2, which has been brought to room temperature by the air cooler 12, is supplied to the heat exchanger 8. Furthermore, the heat exchanger 8 causes the suction air A2, which has been brought to room temperature by the air cooler 12, to exchange heat with the suction air A2 that has just been drawn in from the cooling chamber 101 (the suction air A2, which has been brought to room temperature by the air cooler 12, is pre-cooled).

[0046] Turbine 2 expands the pre-cooled suction air A2 from heat exchanger 8, reducing the temperature and pressure of the suction air A2 (generating cooling air A1). Turbine 2 is connected to and driven by electric motor 14 via another drive shaft 15b. The cooling air A1 generated by turbine 2 flows through air line 6 and is delivered to cooling chamber 101. Turbine 2 operates at a speed corresponding to the rotational speed of electric motor 14. In this disclosure, it is assumed that the rotational speed of turbine 2 is equal to the rotational speed of electric motor 14.

[0047] Control device 4 controls the operation of turbine 2. In one embodiment, control device 4 is electrically connected to electric motor 14, and the speed of turbine 2 is controlled by electric motor 14. Control device 4 is an electronic control device or computer, for example, equipped with a processor such as CPU or GPU (not shown), memory such as ROM or RAM, and I / O interface. Control device 4 implements its various functional units by the processor performing operations (such as calculations) according to the instructions of the program loaded into memory. See reference. Figure 3 The functional units of the control device 4 in the first embodiment will be described below. In several embodiments, the control device 4 is a cloud server installed in a cloud environment.

[0048] Figure 3 This is a schematic functional block diagram of the control device 4 according to the first embodiment. (For example...) Figure 3 As shown, the control device 4 includes a start-up and operation unit 20A.

[0049] In the first embodiment, such as Figure 2 As illustrated, the cooling device 1A also includes an inlet temperature sensor 16 for measuring the inlet temperature T1 of the turbine 2. The control device 4 is electrically connected to the inlet temperature sensor 16 to obtain the inlet temperature T1. When the cooling device 1A is started, the start-up operation unit 20A causes the turbine 2 to run at a first speed X1 until the inlet temperature T1 of the turbine 2 drops below a preset inlet-side predetermined temperature TA. Furthermore, when the inlet temperature T1 of the turbine 2 is below the inlet-side predetermined temperature TA, the start-up operation unit 20A causes the turbine 2 to run at a second speed X2, which is greater than the first speed X1. In addition, the start-up operation unit 20A can detect the start-up of the cooling device 1A, for example, by detecting the connection of a power source (not shown).

[0050] The operation of the start-up unit 20A will be explained in detail. When the cooling device 1A is started, the start-up unit 20A instructs the motor 14 to rotate at a first speed X1. When the motor 14 receives an instruction PA from the start-up unit 20A including the first speed X1, it rotates at the first speed X1. The turbine 2 also operates at the first speed X1, and the cooling chamber 101 is gradually cooled. Furthermore, when the inlet temperature T1 is less than the inlet-side predetermined temperature TA, the start-up unit 20A instructs the motor 14 to rotate at a second speed X2. When the motor 14 receives an instruction PA from the start-up unit 20A including the second speed X2, it rotates at the second speed X2. The turbine 2 also operates at the second speed X2, and the cooling chamber 101 is further cooled. In the first embodiment, the second speed X2 is, for example, the rated speed of the turbine 2. The first speed X1 is a low speed at which the moisture contained in the suction air A2 supplied to the turbine 2 will not freeze. The inlet-side predetermined temperature TA is a temperature of -5 degrees Celsius or higher and 10 degrees Celsius or lower, for example, 0 degrees Celsius.

[0051] (Functions and Effects)

[0052] The air in the cooling chamber 101 before the cooling device 1 is started may contain moisture. Therefore, if the speed of the turbine 2 is increased sharply when the cooling device 1 is started, the moisture contained in the air drawn in from the cooling chamber 101 (suction air A2) may freeze inside the turbine 2. If ice forms inside the turbine 2, the flow rate of the suction air A2 flowing inside the turbine 2 will decrease, which will lead to a decrease in the performance of the cooling device 1.

[0053] According to the first embodiment, when the cooling device 1A is started, the turbine 2 operates at a first speed X1 until the inlet temperature T1 drops below a predetermined inlet temperature TA. When the inlet temperature T1 is below the predetermined inlet temperature TA, it operates at a second speed X2. Therefore, even if moisture contained in the drawn-in air A2 condenses and forms droplets inside the turbine 2 during the period when the turbine 2 operates at the first speed X1, these droplets can be disposed of arbitrarily before freezing. Furthermore, after the drawn-in air A2 is dehydrated, the turbine 2 is operated at the second speed X2 (rated operating speed). Therefore, the formation of ice inside the turbine 2 can be suppressed. As a result, the performance degradation of the cooling device 1A caused by ice formation inside the turbine 2 during startup can be suppressed.

[0054] Additionally, as a method for handling droplets, one approach is to guide the droplets downstream of the nozzle flow path 25 (described later) of the turbine 2 or the cooling chamber 101 by drawing in air A2 or cooling air A1, causing them to freeze. In several embodiments, a cooling device 1A is provided downstream of the turbine 2 from the air line 6 and includes an ice condenser for freezing moisture contained in the cooling air A1. In several embodiments, the turbine 2 is configured to discharge droplets formed within the turbine 2.

[0055] Furthermore, according to the first embodiment, icing within the turbine 2 is suppressed by controlling the operation of the turbine 2, and no new icing suppression device is required. Therefore, it is possible to suppress the enlargement of the cooling device 1A and to suppress performance degradation caused by icing within the turbine 2 during startup. In particular, the size of the cooling device 1A is limited by the refrigerated container 100, therefore the cooling device 1A of this disclosure is advantageous.

[0056] In addition, according to Figure 2 The illustrated cooling device 1A, compared to the cooling device 1C described later, is able to cool the cooling chamber 101 more quickly.

[0057] Cooling device

[0058] (structure)

[0059] The cooling device 1B(1) of the second embodiment will be described. Figure 4This is a diagram that schematically illustrates the structure of the cooling device 1B according to the second embodiment. Figure 5 This is a schematic functional block diagram of the control device 4 according to the second embodiment. The cooling device 1B of the second embodiment differs from the cooling device 1A of the first embodiment in that it controls the operation of the turbine 2 based on the outlet temperature T2 of the turbine 2. In the second embodiment, the same reference numerals are used to denote the same components as in the first embodiment, and detailed descriptions thereof are omitted.

[0060] In the second embodiment, such as Figure 4 As illustrated, the cooling device 1B includes an outlet temperature sensor 17 for measuring the outlet temperature T2 of the turbine 2. The control device 4 is electrically connected to the outlet temperature sensor 17 to obtain the outlet temperature T2. Figure 5 As shown, the control device 4 includes a start-up operation unit 20B. When the cooling device 1 is started, the start-up operation unit 20B causes the turbine 2 to run at a first speed X1 until the outlet temperature T2 drops below a preset outlet side specified temperature TB. When the outlet temperature T2 is below the outlet side specified temperature TB, the turbine 2 is started at a second speed X2. In addition, the start-up operation unit 20B can detect the start-up of the cooling device 1B, for example, by detecting the connection of a power source (not shown).

[0061] The operation of the start-up unit 20B will be explained in detail. When the cooling device 1A is started, the start-up unit 20B instructs the motor 14 to rotate at a first speed X1. Upon receiving an instruction PB from the start-up unit 20B including the first speed X1, the motor 14 rotates at the first speed X1. Simultaneously, the turbine 2 also operates at the first speed X1, and the cooling chamber 101 is gradually cooled. Furthermore, when the outlet temperature T2 is lower than the specified outlet temperature TB, the start-up unit 20B instructs the motor 14 to rotate at a second speed X2. Upon receiving an instruction PB from the start-up unit 20B including the second speed X2, the motor 14 rotates at the second speed X2. Simultaneously, the turbine 2 also operates at the second speed X2, and the cooling chamber 101 is further cooled. In the second embodiment, the second speed X2 is, for example, the rated speed of the turbine 2. The first speed X1 is a low speed at which the moisture contained in the suction air A2 supplied to the turbine 2 will not freeze. The specified outlet temperature TB is a temperature of -5 degrees Celsius or higher and 10 degrees Celsius or lower, for example, 0 degrees Celsius.

[0062] (Functions and Effects)

[0063] According to the second embodiment, when the cooling device 1B is started, the turbine 2 operates at a first speed X1 until the outlet temperature T2 drops below the specified outlet temperature TB. When the outlet temperature T2 is below the specified outlet temperature TB, it operates at a second speed X2. Therefore, even if moisture contained in the drawn-in air A2 condenses and forms droplets inside the turbine 2 during the period when the turbine 2 operates at the first speed X1, these droplets can be disposed of arbitrarily before freezing. Furthermore, after the drawn-in air A2 is dehydrated, the turbine 2 is operated at the second speed X2 (rated operating speed). Therefore, the formation of ice inside the turbine 2 can be suppressed. Thus, the performance degradation of the cooling device 1B caused by ice formation inside the turbine 2 during startup can be suppressed. Specific examples of the method for handling droplets are described above.

[0064] Moreover, according to Figure 4 The illustrated cooling device 1B suppresses icing within the turbine 2 by controlling its operation, without requiring additional icing suppression devices. Therefore, it is possible to prevent the cooling device 1B from becoming too large and to suppress performance degradation caused by icing within the turbine 2 during startup. In particular, the size of the cooling device 1B is limited by the refrigerated container 100, thus the cooling device 1B of this disclosure is advantageous.

[0065] In addition, according to Figure 4 The illustrated cooling device 1B, compared to the cooling device 1C described later, is able to cool the cooling chamber 101 more quickly.

[0066] Cooling device

[0067] (structure)

[0068] The cooling device 1C(1) of the third embodiment will be described. Figure 6 This is a diagram that schematically illustrates the structure of the cooling device 1C according to the third embodiment. Figure 7 This is a schematic functional block diagram of the control device 4 according to the third embodiment. In the cooling device 1C of the third embodiment, the operation of the turbine 2 is controlled based on the inlet temperature T1 and the outlet temperature T2 of the turbine 2, respectively, unlike the cooling device 1A of the first embodiment and the cooling device 1B of the second embodiment described above. In the third embodiment, the same reference numerals are used to denote the same components as those in the first and second embodiments, and detailed descriptions thereof are omitted.

[0069] In the third embodiment, such as Figure 6 As illustrated, the cooling device 1C includes an inlet temperature sensor 16 and an outlet temperature sensor 17. The control device 4 is electrically connected to the inlet temperature sensor 16 and the outlet temperature sensor 17 respectively, and obtains the inlet temperature T1 and the outlet temperature T2. Figure 7As shown, the control device 4 includes a start-up operation unit 20C. When the cooling device 1C is started, the start-up operation unit 20C causes the turbine 2 to operate at a first speed X1 until the outlet temperature T2 drops below the specified outlet temperature TB. Furthermore, when the outlet temperature T2 is below the specified outlet temperature TB, the turbine 2 is operated at a second speed X2. The turbine 2 is then operated at the second speed X2 until the inlet temperature T1 drops below the specified inlet temperature TA. When the inlet temperature T1 is below the specified inlet temperature TA, the turbine is operated at a third speed X3, which is greater than the second speed X2. Additionally, the start-up operation unit 20C can detect the start-up of the cooling device 1C, for example, by detecting when a power source (not shown) is turned on.

[0070] The operation of the start-up unit 20C will be described in detail. When the cooling device 1A is started, the start-up unit 20C instructs the motor 14 to rotate at a first speed X1. Upon receiving the instruction PC from the start-up unit 20C including the first speed X1, the motor 14 rotates at the first speed X1. Simultaneously, the turbine 2 also operates at the first speed X1, and the cooling chamber 101 is gradually cooled. Furthermore, when the outlet temperature T2 is lower than the specified outlet temperature TB, the start-up unit 20C instructs the motor 14 to rotate at a second speed X2. Upon receiving the instruction PC from the start-up unit 20C including the second speed X2, the motor 14 rotates at the second speed X2. Simultaneously, the turbine 2 also operates at the second speed X2, and the cooling chamber 101 is further cooled. The start-up unit 20C maintains the turbine 2 operating at the second speed X2 until the inlet temperature T1 drops below the specified inlet temperature TA. Furthermore, when the inlet temperature T1 is lower than the specified inlet temperature TA, the start-up unit 20C instructs the motor 14 to rotate at a third speed X3. When the motor 14 receives an instruction PC from the start-up unit 20C indicating a third rotational speed X3, it rotates at the third rotational speed X3. Furthermore, the turbine 2 also operates at the third rotational speed X3, further cooling the cooling chamber 101.

[0071] In the third embodiment, the third rotational speed X3 is, for example, the rated rotational speed of turbine 2. The first rotational speed X1 is a low rotational speed at which the moisture in the suction air A2 supplied to turbine 2 will not freeze. The second rotational speed X2 is a medium rotational speed that is lower than the third rotational speed X3 but higher than the first rotational speed X1. The inlet-side temperature TA is specified to be a temperature of -5 degrees Celsius or higher and lower than 10 degrees Celsius, for example, 0 degrees Celsius. The outlet-side temperature TB is specified to be a temperature of -5 degrees Celsius or higher and lower than 10 degrees Celsius, for example, 0 degrees Celsius.

[0072] (Functions and Effects)

[0073] according to Figure 6The illustrated cooling device 1C (third embodiment) operates as follows: when the cooling device 1C is started, the turbine 2 operates at a first speed X1 until the outlet temperature T2 drops below a predetermined outlet temperature TB. When the outlet temperature T2 is below the predetermined outlet temperature TB, it operates at a second speed X2. Furthermore, the turbine 2 maintains operation at the second speed X2 until the inlet temperature T1 drops below a predetermined inlet temperature TA. When the inlet temperature T1 is below the predetermined inlet temperature TA, it operates at a third speed X3. Therefore, even if moisture contained in the drawn-in air A2 condenses and forms droplets inside the turbine 2 during operation at the first speed X1 or the second speed X2, these droplets can be disposed of before freezing. After the drawn-in air A2 is dehydrated, the turbine 2 is operated at a third speed X3 (rated operating speed). Therefore, the formation of ice inside the turbine 2 can be suppressed. Thus, the performance degradation of the cooling device 1C caused by ice formation inside the turbine 2 during startup can be suppressed. Specific examples of the droplet disposal method are described above.

[0074] Moreover, according to Figure 6 The illustrated cooling device 1C suppresses icing within the turbine 2 by controlling its operation, without requiring additional icing suppression devices. Therefore, it is possible to prevent the cooling device 1C from becoming too large and to suppress performance degradation caused by icing within the turbine 2 during startup. In particular, the size of the cooling device 1C is limited by the refrigerated container 100, thus the cooling device 1C of this disclosure is advantageous.

[0075] In addition, according to Figure 6 The illustrated cooling device 1C operates the turbine 2 at three speeds (low speed, medium speed, and high speed) from a first speed X1 to a third speed X3, based on the outlet temperature T2 and the inlet temperature T1. Therefore, compared to the cooling device 1A of the first embodiment and the cooling device 1B of the second embodiment, it can increase the amount of droplets formed by the condensation of moisture contained in the air A2. In other words, it can further suppress performance degradation caused by icing inside the turbine 2 during startup.

[0076] <Turbo>

[0077] (structure)

[0078] An example of the specific structure of turbine 2 will be described. Figure 8 This is a diagram that schematically illustrates the structure of turbine 2 according to one embodiment. (As shown...) Figure 8 As illustrated, the turbine 2 includes: a turbine rotor 22, a vortex flow path forming portion 24 forming a vortex flow path 23 on the outer peripheral side of the turbine rotor 22, and a nozzle flow path forming portion 26 forming a nozzle flow path 25 for guiding the suction air A2 from the vortex flow path 23 to the turbine rotor 22.

[0079] exist Figure 8 In the illustrated configuration, the turbine 2 includes a housing 21 that houses the turbine rotor 22 as a rotatable component. The housing 21 has a vortex flow path forming section 24, a nozzle flow path forming section 26, and an exhaust flow path forming section 44. The turbine rotor 22 includes a plurality of moving blades 35 that rotate in response to the flow of suction air A2. The turbine rotor 22 is connected to a drive shaft 15b.

[0080] Hereinafter, the direction in which the axis O of the turbine rotor 22 extends is defined as the axial direction D1, the drive shaft 15b side in the axial direction D1 is defined as the rear end side of the axial direction D1, and the side opposite to the rear end side is defined as the front end side of the axial direction D1. In addition, the direction orthogonal to the axis O is defined as the radial direction D2, the direction in the radial direction D2 that is close to the axis O is defined as the inner side of the radial direction D2, and the direction that is away from the axis O is defined as the outer side of the radial direction D2.

[0081] The vortex flow path forming section 24 has a vortex flow path surface 30 as a surface facing the vortex flow path 23. The vortex flow path 23 is a vortex flow path used to guide the suction air A2 flowing into the turbine 2 to the turbine rotor 22. The vortex flow path 23 extends circumferentially along the axis O at the outer side (outer peripheral side of the turbine rotor 22) on the radially D2 side of the turbine rotor 22.

[0082] The nozzle flow path forming section 26 has a nozzle flow surface 32 as a surface facing the nozzle flow path 25. The nozzle flow path 25 is a flow path for guiding suction air A2 from the vortex flow path 23 to the turbine rotor 22, which is disposed radially D2 inwardly than the vortex flow path 23. The nozzle flow path 25 is formed between the vortex flow path 23 and the turbine rotor 22 in such a way that it surrounds the outer side of the turbine rotor 22 radially D2. The suction air A2 flowing into the turbine 22 is guided from the outer side of the turbine rotor 22 radially D2 towards the turbine rotor 22 after flowing in the order of the vortex flow path 23 and the nozzle flow path 25.

[0083] The discharge flow path forming part 44 has an outlet 46 for discharging cooling air A1 from the turbine 2 at its front end in the axial direction D1. The discharge flow path forming part 44 has an internal discharge flow path 45 for conveying the suction air A2 (cooling air A1) that drives the turbine rotor 22 to rotate to the outlet 46.

[0084] In one embodiment, the vortex flow path forming portion 24 and the nozzle flow path forming portion 26 are both hydrophobic. Figure 9 This is a diagram used to illustrate the "hydrophobicity" in this disclosure. For example... Figure 9As shown, with a droplet 202 of pure water attached to an object 200 for which hydrophobicity is being measured (evaluated), if the tangent to the surface 203 of the droplet 202 at point P1 where it contacts the surface 201 of the object 200 and the surface 203 of the droplet 202 is defined as L, then the angle on the side where the droplet 202 exists within the angle formed by the tangent L and the surface 201 of the object 200 is defined as the contact angle θ. In this disclosure, "having hydrophobicity" means that the contact angle θ is 90 degrees or more. Furthermore, the method for measuring this contact angle θ is not particularly limited; for example, it can be measured using a contact angle meter (Kyowa Interface Science Co., Ltd., product name: Fully Automatic Contact Angle Meter DMo-902).

[0085] In one embodiment, the vortex flow path forming section 24 and the nozzle flow path forming section 26 are both made of aluminum alloy. In one embodiment, the vortex flow path forming section 24 is treated with a hydrophobic coating on the vortex flow path 30 to form a hydrophobic layer M. Furthermore, the nozzle flow path forming section 26 is treated with a hydrophobic coating on the nozzle flow path 32 to form a hydrophobic layer M. The housing 21 is treated with a hydrophobic coating on the entire surface facing the flow path through which the suction air A2 flows, forming a hydrophobic layer M. That is, a hydrophobic layer M is also formed on the surface of the discharge flow path forming section 44 facing the discharge flow path 45.

[0086] Figure 10 This is an enlarged perspective view of a portion of the vortex flow path forming section 24 according to one embodiment. In one embodiment, as... Figure 10 As illustrated, the vortex flow path forming section 24 has a vortex flow path groove 36 formed on the vortex flow path 30, extending along the flow direction Da of the suction air A2 flowing in the vortex flow path 23. Furthermore, the width W1 of the vortex flow path groove 36 is 0.01 mm or more and 0.5 mm or less. This vortex flow path groove 36 is formed to extend obliquely at an angle within ±45 degrees relative to the flow direction Da of the suction air A2 flowing in the vortex flow path 23. Figure 10 In the illustrated configuration, the vortex flow path forming section 24 forms a plurality of vortex flow path grooves 36 on the vortex flow path 30. The plurality of vortex flow path grooves 36 are arranged at intervals along a direction intersecting the flow direction Da of the suction air A2 flowing in the vortex flow path 23. If the size of this interval (spacing) is set to W3, then it satisfies 0.9 × W1. <W3 <1.1×W1。

[0087] Figure 11 This is an enlarged perspective view of a portion of the nozzle flow path forming section 26 according to one embodiment. In one embodiment, as... Figure 11As illustrated, the nozzle flow path forming section 26 has a nozzle flow path groove 38 formed on the nozzle flow path surface 32, extending along the flow direction Db of the suction air A2 flowing in the nozzle flow path 25. Furthermore, the width W2 of the nozzle flow path groove 38 is 0.01 mm or more and 0.5 mm or less. This nozzle flow path groove 38 is formed to extend obliquely with respect to the flow direction Db of the suction air A2 flowing in the nozzle flow path 25 at an angle within ±45 degrees. Figure 11 In the illustrated configuration, the nozzle flow path forming section 26 forms a plurality of nozzle flow path grooves 38 on the nozzle flow path surface 32. The plurality of nozzle flow path grooves 38 are arranged at intervals along a direction intersecting the flow direction Db of the suction air A2 flowing in the nozzle flow path 25. If the size of this interval (pitch) is set to W4, then it satisfies 0.9 × W2. <W4 <1.1×W4。

[0088] Figure 12 This is a schematic diagram illustrating the internal structure of the turbine 2 according to one embodiment, viewed from the front end side along the axial direction D1. In one embodiment, as... Figure 12 As illustrated, the turbine 2 also includes a plurality of nozzle blades 40 spaced apart on the nozzle flow path 25 in the circumferential direction D3. Furthermore, the nozzle blades 40 are treated with a hydrophobic coating on their surface 42 facing the nozzle flow path 25, forming a hydrophobic layer M. However, the nozzle blades 40 are not grooved on their surface 42 facing the nozzle flow path 25. In one embodiment, the number of nozzle blades 40 is less than the number of moving blades 35.

[0089] (Functions and Effects)

[0090] The nozzle flow path 25 in the flow path that draws in air A2 has a relatively narrow cross-section, which makes it more susceptible to icing when droplets form. Therefore, it is preferable to actively suppress icing on the nozzle flow path 25. The cross-section of the discharge flow path 45 is larger than that of the nozzle flow path 25. Therefore, in the turbine 2 according to one embodiment, the vortex flow path forming portion 24 and the nozzle flow path forming portion 26 are both hydrophobic, so that even if moisture contained in the drawn-in air A2 condenses and forms droplets in the vortex flow path 23 or the nozzle flow path 25, these droplets can be guided towards the discharge flow path 45, thus suppressing icing on the nozzle flow path 25.

[0091] According to one embodiment of the turbine 2, the vortex flow path forming portion 24 and the nozzle flow path forming portion 26 are both made of aluminum alloy, thus exhibiting hydrophobicity. However, this disclosure is not limited to the vortex flow path forming portion 24 and the nozzle flow path forming portion 26 being made of aluminum alloy. In several embodiments, one of the vortex flow path forming portion 24 and the nozzle flow path forming portion 26 is made of aluminum alloy. The vortex flow path forming portion 24 and the nozzle flow path forming portion 26 may also be made of materials other than aluminum alloy, thus exhibiting hydrophobicity.

[0092] According to one embodiment of the turbine 2, hydrophobic layers M are formed on the vortex flow surface 30 and the nozzle flow surface 32, respectively. Therefore, the vortex flow surface 30 and the nozzle flow surface 32 are each capable of being hydrophobic. However, this disclosure is not limited to forming hydrophobic layers M on the vortex flow surface 30 and the nozzle flow surface 32 separately. In several embodiments, the hydrophobic layer M is formed on one of the vortex flow surface 30 and the nozzle flow surface 32.

[0093] According to one embodiment of the turbine 2, the vortex flow path forming section 24 is made of aluminum alloy, and a hydrophobic layer M is formed on the vortex flow path 30, thereby achieving higher hydrophobicity compared to either of the two embodiments. However, this disclosure is not limited to this method. In several embodiments, the vortex flow path forming section 24 is made of aluminum alloy, but the hydrophobic layer M is not formed on the vortex flow path 30. In several embodiments, the vortex flow path forming section 24 is made of a material with lower hydrophobicity than aluminum alloy, and a hydrophobic layer M is formed on the vortex flow path 30. The same applies to the nozzle flow path forming section 26.

[0094] Generally, it is known that hydrophobicity is improved (superhydrophobicity) by forming grooves on a hydrophobic surface. According to one embodiment of the turbine 2, a vortex flow path groove 36 is formed in the vortex flow path 30, and a nozzle flow path groove 38 is formed in the nozzle flow path 32. Therefore, both the vortex flow path 30 and the nozzle flow path 32 can improve hydrophobicity.

[0095] In the case where the turbine 2 has nozzle blades 40, if grooves are formed on the surface of the nozzle blades 40 to improve their hydrophobicity, it may lead to a decrease in the performance of the nozzle blades 40. According to one embodiment of the turbine 2, the nozzle blades 40 are treated with a hydrophobic coating without groove processing, thus suppressing performance degradation and increased manufacturing costs, and also possessing hydrophobicity.

[0096] According to one embodiment of the turbine 2, the number of nozzle blades 40 is less than the number of moving blades 35. Therefore, the number of nozzle blades 40 subjected to hydrophobic coating treatment can be reduced, thus lowering manufacturing costs. Moreover, the total area (wetting surface area) of the nozzle blades 40 facing the nozzle flow path 25 can be reduced, further suppressing icing in the nozzle flow path 25.

[0097] In one embodiment of the turbine 2, both the vortex flow path forming portion 24 and the nozzle flow path forming portion 26 are configured to be hydrophobic, but this disclosure is not limited to this configuration. It is also possible for only the nozzle flow path forming portion 26 to be hydrophobic. In several embodiments, the nozzle flow path forming portion 26 is made of aluminum alloy, and a nozzle flow path groove 38 with a width of 0.01 mm or more and 0.5 mm or less is formed on the nozzle flow path surface 32, extending along the flow direction Db of the suction air A2 flowing in the nozzle flow path 25. Furthermore, the nozzle flow path surface 32 is treated with a hydrophobic coating. Moreover, the nozzle blade 40 is treated with a hydrophobic coating on the surface facing the nozzle flow path 25, and no groove forming is performed on the surface facing the nozzle flow path 25.

[0098] Compared to other flow paths formed on the turbine 2, the nozzle flow path 25 has a narrower cross-section. Therefore, it is important to guide droplets within the nozzle flow path 25 downstream to suppress icing. According to the above structure, the nozzle flow path forming part 26 is made of aluminum alloy, and a hydrophobic coating is applied to the nozzle flow surface 32, thus giving the nozzle flow surface 32 high hydrophobicity. Furthermore, although the nozzle blade 40 is not grooved, it is treated with a hydrophobic coating, thus reducing performance degradation and increasing manufacturing costs while maintaining hydrophobicity. Therefore, droplets within the nozzle flow path 25 can be guided downstream to suppress icing within the nozzle flow path 25.

[0099] <Operating Method of Cooling Device>

[0100] Figure 13 This is a flowchart illustrating the operation method of a cooling device 1 according to one embodiment. The cooling device 1 includes a turbine 2 that expands air drawn in from the cooling chamber 101 to cool the cooling chamber 101 of the refrigerated container 100. (Example...) Figure 13 As shown, the operation method of the cooling device 1 according to one embodiment includes a first start-up operation step SA. In this first start-up operation step SA, when the cooling device 1 is started, the turbine 2 is operated at a first speed X1 until the inlet temperature T1 of the turbine 2 drops below a predetermined inlet temperature TA (0 degrees). When the inlet temperature T1 of the turbine 2 is below the predetermined inlet temperature TA, the turbine is operated at a second speed X2. The operation method of the cooling device 1 according to this embodiment begins when the cooling device 1 is started and ends when the turbine 2 is operated at the second speed X2.

[0101] The first start-up operation step SA includes: a low-speed operation step SA1, an inlet temperature determination step SA2, and a high-speed operation step SA3. In the low-speed operation step SA1, the turbine 2 is operated at a first speed X1. When the cooling device 1 is started, the low-speed operation step SA1 is executed. In the inlet temperature determination step SA2, after executing the low-speed operation step SA1, it is determined whether the inlet temperature T1 of the turbine 2 is less than the specified inlet temperature TA. If the inlet temperature T1 of the turbine 2 is less than the specified inlet temperature TA (SA2: Yes), the high-speed operation step SA3 is entered. If the inlet temperature T1 of the turbine 2 is greater than or equal to the specified inlet temperature TA (SA2: No), the process returns to the low-speed operation step SA1. In the high-speed operation step SA3, the turbine 2 is operated at a second speed X2. When the high-speed operation step SA3 is executed, the operation method of the cooling device 1 according to one embodiment ends.

[0102] Figure 14 This is a flowchart illustrating the operation method of a cooling device 1 according to another embodiment. The cooling device 1 includes a turbine 2 that expands air drawn in from the cooling chamber 101 to cool the cooling chamber 101 of the refrigerated container 100. (Example...) Figure 14 As shown, the operation method of the cooling device 1 in another embodiment includes a second start-up operation step SB. In this second start-up operation step SB, when the cooling device 1 is started, the turbine 2 is operated at a first speed X1 until the outlet temperature T2 of the turbine 2 drops below a predetermined outlet temperature TB (0 degrees). When the outlet temperature T2 of the turbine 2 is below the predetermined outlet temperature TB, the turbine 2 is operated at a second speed X2. The operation method of the cooling device 1 in this other embodiment begins when the cooling device 1 is started and ends when the turbine 2 is operated at the second speed X2.

[0103] The second start-up operation step SB includes: a low-speed operation step SB1, an outlet temperature determination step SB2, and a high-speed operation step SB3. In the low-speed operation step SB1, the turbine 2 is operated at a first speed X1. When the cooling device 1 is started, the low-speed operation step SB1 is executed. In the outlet temperature determination step SB2, after executing the low-speed operation step SB1, it is determined whether the outlet temperature T2 of the turbine 2 is less than the specified outlet temperature TB. If the outlet temperature T2 of the turbine 2 is less than the specified outlet temperature TB (SB2: Yes), the high-speed operation step SB3 is entered. If the outlet temperature T2 of the turbine 2 is greater than or equal to the specified outlet temperature TB (SA2: No), the process returns to the low-speed operation step SB1. In the high-speed operation step SB3, the turbine 2 is operated at a second speed X2. When the high-speed operation step SB3 is executed, the operation method of the cooling device 1 according to another embodiment ends.

[0104] Figure 15This is a flowchart illustrating the operation method of a cooling device 1 according to another embodiment. The cooling device 1 includes a turbine 2 that expands air drawn in from the cooling chamber 101 to cool the cooling chamber 101 of the refrigerated container 100. (Example...) Figure 15 As shown, the operation method of the cooling device 1 in another embodiment includes a third start-up operation step SC. In this third start-up operation step SC, when the cooling device 1 is started, the turbine 2 is operated at a first speed X1 until the outlet temperature T2 of the turbine 2 drops below the specified outlet temperature TB (0 degrees). When the outlet temperature T2 of the turbine 2 is below the specified outlet temperature TB, the turbine 2 is operated at a second speed X2. The turbine 2 is operated at a second speed X2 until the inlet temperature T1 of the turbine 2 drops below the specified inlet temperature TA (0 degrees). When the inlet temperature T1 of the turbine 2 is below the specified inlet temperature TA, the turbine 2 is operated at a third speed X3.

[0105] The third start-up operation step SC includes: low-speed operation step SC1, outlet temperature determination step SC2, medium-speed operation step SC3, inlet temperature determination step SC4, and high-speed operation step SC5. In the low-speed operation step SC1, turbine 2 is operated at a first speed X1. Low-speed operation step SC1 is executed when cooling device 1 is started. In the outlet temperature determination step SC2, after executing low-speed operation step SC1, it is determined whether the outlet temperature T2 of turbine 2 is less than the specified outlet temperature TB. If the outlet temperature T2 of turbine 2 is less than the specified outlet temperature TB (SC2: Yes), the process proceeds to medium-speed operation step SC3. If the outlet temperature T2 of turbine 2 is above the specified outlet temperature TB (SC2: No), the process returns to low-speed operation step SC1. In the medium-speed operation step SC3, turbine 2 is operated at a second speed X2. In the inlet temperature determination step SC4, after executing medium-speed operation step SC3, it is determined whether the inlet temperature T1 of turbine 2 is less than the specified inlet temperature TA. If the inlet temperature T1 of turbine 2 is less than the specified inlet temperature TA (SC4: Yes), proceed to high-speed operation step SC5. If the inlet temperature T1 of turbine 2 is greater than or equal to the specified inlet temperature TA (SC4: No), return to medium-speed operation step SC3. In high-speed operation step SC5, turbine 2 is operated at a third speed X3. When high-speed operation step SC5 is executed, the operation method of cooling device 1 according to another embodiment ends.

[0106] The contents described in the above embodiments are as follows.

[0107] [1] The cooling device (1A) disclosed herein is a cooling device for cooling the cooling chamber (101) of a freezer (100), and the cooling device (1A) comprises: The turbine (2) expands the air (A2) drawn in from the aforementioned cooling chamber; and Control device (4) controls the operation of the aforementioned turbine. The control device includes a start-up unit (20A). When the cooling device is started, the start-up unit (20A) causes the turbine to run at a first speed (X1) until the inlet temperature (T1) of the turbine drops to less than a preset inlet side specified temperature (TA). When the inlet temperature of the turbine is less than the preset inlet side specified temperature, the start-up unit (20A) causes the turbine to run at a second speed (X2) that is greater than the first speed.

[0108] The air in the cooling chamber before the cooling device is started sometimes contains moisture. Therefore, if the turbine speed is increased sharply when the cooling device is started, the moisture in the air drawn in from the cooling chamber may freeze inside the turbine. If ice forms inside the turbine, the airflow inside the turbine will decrease, resulting in a decrease in the performance of the cooling device. According to the structure described above [1], when the cooling device is started, the turbine operates at a first speed until the turbine inlet temperature drops below the specified inlet temperature, and operates at a second speed when the turbine inlet temperature is below the specified inlet temperature. Therefore, by appropriately setting the specified inlet temperature, even if the moisture in the air drawn in from the cooling chamber condenses and forms droplets, it is possible to suppress the freezing inside the turbine. Therefore, it is possible to suppress the decrease in the performance of the cooling device caused by freezing inside the turbine during startup.

[0109] Furthermore, according to the structure described above [1], icing inside the turbine is suppressed by controlling the operation of the turbine, without the need for additional devices to suppress icing. Therefore, it is possible to suppress the enlargement of the cooling device and to suppress the performance degradation caused by icing inside the turbine during startup. In particular, the cooling device disclosed herein is advantageous because refrigerated containers limit the size of the cooling device.

[0110] [2] The cooling device (1B) of the present invention is a cooling device for cooling the cooling chamber (101) of a freezer (100), and the cooling device (1B) includes: The turbine (2) expands the air (A2) drawn in from the aforementioned cooling chamber; and Control device (4) controls the operation of the aforementioned turbine. The control device includes a start-up unit (20B). When the cooling device is started, the start-up unit (20B) causes the turbine to run at a first speed (X1) until the outlet temperature (T2) of the turbine drops to less than a preset outlet side specified temperature (TB). When the outlet temperature of the turbine is less than the outlet side specified temperature, the start-up unit (20B) causes the turbine to run at a second speed (X2) that is greater than the first speed.

[0111] According to the structure described above [2], when the cooling device is started, the turbine operates at a first speed until the turbine outlet temperature drops below the specified outlet temperature, and then operates at a second speed when the turbine outlet temperature is below the specified outlet temperature. Therefore, by appropriately setting the specified outlet temperature, even if moisture contained in the air drawn in from the cooling chamber condenses and forms droplets, icing into the turbine can be suppressed. Therefore, the performance degradation of the cooling device caused by icing in the turbine during startup can be suppressed.

[0112] Furthermore, according to the structure described above [2], icing inside the turbine is suppressed by controlling the operation of the turbine, without the need for additional devices to suppress icing. Therefore, it is possible to suppress the enlargement of the cooling device and to suppress the performance degradation caused by icing inside the turbine during startup. In particular, the cooling device disclosed herein is advantageous because refrigerated containers limit the size of the cooling device.

[0113] [3] The cooling device (1C) disclosed herein is a cooling device for cooling the cooling chamber (101) of a freezer (100), and the cooling device (1C) comprises: The turbine (2) expands the air (A2) drawn in from the aforementioned cooling chamber; and Control device (4) controls the operation of the aforementioned turbine. The control device includes a start-up unit (20C). When the cooling device is started, the start-up unit (20C) causes the turbine to run at a first speed (X1) until the outlet temperature (T2) of the turbine drops below a preset outlet side specified temperature (TB). When the outlet temperature of the turbine is lower than the preset outlet side specified temperature, the start-up unit (20C) causes the turbine to run at a second speed (X2) greater than the first speed, and causes the turbine to run at the second speed until the inlet temperature (T1) of the turbine drops below a preset inlet side specified temperature (TA). When the inlet temperature of the turbine is lower than the preset inlet side specified temperature, the start-up unit (20C) causes the turbine to run at a third speed (X3) greater than the second speed.

[0114] According to the structure described above [3], when the cooling device is started, the turbine operates at a first speed until the turbine outlet temperature drops below the specified outlet temperature, and then operates at a second speed when the turbine outlet temperature is below the specified outlet temperature. Furthermore, the turbine operates at a second speed until the turbine inlet temperature drops below the specified inlet temperature, and then operates at a third speed when the turbine inlet temperature is below the specified inlet temperature. Therefore, by appropriately setting the specified outlet temperature and the specified inlet temperature respectively, even if moisture contained in the air drawn in from the cooling chamber condenses and forms droplets, icing inside the turbine can be suppressed. Therefore, the performance degradation of the cooling device caused by icing inside the turbine during startup can be suppressed.

[0115] Furthermore, according to the structure described above [3], icing inside the turbine is suppressed by controlling the operation of the turbine, without the need for additional devices to suppress icing. Therefore, it is possible to suppress the enlargement of the cooling device and to suppress the performance degradation caused by icing inside the turbine during startup. In particular, the cooling device disclosed herein is advantageous because refrigerated containers limit the size of the cooling device.

[0116] Moreover, according to the structure described above [3], the turbine is operated in three stages from the first speed to the third speed, depending on the turbine outlet temperature and the turbine inlet temperature. Therefore, compared with the above [1] and above [2] respectively, the amount of droplets (hereinafter referred to as droplets) formed by the condensation of moisture contained in the air drawn in from the cooling chamber can be increased.

[0117] [4] In several embodiments, based on the structure described in any one of [1] to [3] above, The aforementioned turbine includes: Turbine rotor (22); A vortex flow path forming section (24) forms a vortex flow path (23) on the outer periphery of the aforementioned turbine rotor; and The nozzle flow path forming section (26) forms a nozzle flow path (25) for guiding the air from the aforementioned vortex flow path to the aforementioned turbine rotor. The aforementioned vortex flow path forming part and the aforementioned nozzle flow path forming part are both hydrophobic.

[0118] The flow path cross-section of the nozzle flow path becomes narrower, which has a greater impact on droplet icing. Therefore, it is desirable to actively suppress icing towards the nozzle flow path. According to the structure described above [4], the vortex flow path forming part and the nozzle flow path forming part are hydrophobic, thereby guiding the droplets to the downstream side of the turbine than the nozzle flow path and suppressing icing towards the nozzle flow path.

[0119] [5] In several embodiments, based on the structure described in [4] above, The aforementioned vortex flow path forming part and the aforementioned nozzle flow path forming part are respectively made of aluminum alloy.

[0120] According to the structure described above [5], the vortex flow path forming part and the nozzle flow path forming part can be hydrophobic.

[0121] [6] In several embodiments, based on the structure described in [4] or [5] above, The aforementioned vortex flow path forming part has been treated with a hydrophobic coating on the surface (30) facing the aforementioned vortex flow path. The nozzle flow path forming part is treated with a hydrophobic coating on the surface (32) facing the nozzle flow path.

[0122] According to the structure described above [6], the surface facing the vortex flow path and the surface facing the nozzle flow path can be hydrophobic.

[0123] [7] In several embodiments, based on the structure described in any one of [4] to [6] above, The aforementioned vortex flow path forming section has a vortex flow path groove (36) extending along the flow direction (Da) of the air flowing in the aforementioned vortex flow path on its surface facing the aforementioned vortex flow path. The width (W1) of the aforementioned vortex flow channel is greater than 0.01 mm and less than 0.5 mm.

[0124] Generally, it is known that hydrophobicity is improved (superhydrophobicity) by forming grooves on a hydrophobic surface. According to the structure described above [7], the hydrophobicity of the surface facing the vortex flow path can be further improved.

[0125] [8] In several embodiments, based on the structure described in any one of [4] to [7] above, The nozzle flow path forming portion has a nozzle flow path groove (38) extending along the flow direction (Db) of the air flowing in the nozzle flow path on its surface facing the nozzle flow path. The width (W2) of the above-mentioned nozzle flow path groove is 0.01 mm or more and 0.5 mm or less.

[0126] According to the structure described above [8], the hydrophobicity of the surface facing the nozzle flow path can be further improved.

[0127] [9] In several embodiments, based on the structure described in any one of [4] to [8] above, The turbine also includes a plurality of nozzle blades (40) arranged at intervals on the circumferential (D3) axis of the turbine rotor in the nozzle flow path. The nozzle blades are coated with a hydrophobic coating on the surface facing the nozzle flow path, and no groove forming is performed on the surface facing the nozzle flow path.

[0128] According to the structure described above [9], a turbine with nozzle blades can be used. Moreover, although the nozzle blades are not grooved, they are treated with a hydrophobic coating, which can suppress performance degradation and increase manufacturing costs, and is hydrophobic.

[0129]

[10] In several embodiments, based on the structure described in [9] above, The turbine rotor described above includes multiple moving blades (35), and the number of the multiple nozzle blades is less than the number of the multiple moving blades.

[0130] According to the structure described above

[10] , the number of nozzle blades subjected to hydrophobic coating treatment can be reduced, thereby reducing manufacturing costs. Moreover, the total area (wetting surface area) of the nozzle blades facing the nozzle flow path can be reduced, further suppressing icing towards the nozzle flow path.

[0131]

[11] In several embodiments, based on the structure described in any one of [1] to [3] above, The aforementioned turbine includes: Turbine rotor; A vortex flow path forming section forms a vortex flow path on the outer periphery of the aforementioned turbine rotor; A nozzle flow path forming section forms a nozzle flow path for guiding the air from the aforementioned vortex flow path to the aforementioned turbine rotor; and Multiple nozzle blades are arranged at intervals in the nozzle flow path circumferentially on the turbine rotor. The nozzle flow path forming part mentioned above is made of aluminum alloy. The aforementioned nozzle flow path forming portion has a nozzle flow path groove with a width of 0.01 mm or more and 0.5 mm or less, extending along the flow direction of the air flowing in the nozzle flow path, and a hydrophobic coating treatment is applied to the surface facing the nozzle flow path. The nozzle blades are coated with a hydrophobic coating on the surface facing the nozzle flow path, and no groove forming is performed on the surface facing the nozzle flow path.

[0132] Compared to other flow paths formed on the turbine, the nozzle flow path has a narrower cross-section. Therefore, it is important to guide the droplets in the nozzle flow path downstream and suppress icing in the nozzle flow path. According to the structure described above

[11] , the nozzle flow path forming part is made of aluminum alloy and a hydrophobic coating is applied to the surface facing the nozzle flow path, thus exhibiting high hydrophobicity. Moreover, although the nozzle blades are not grooved, a hydrophobic coating is applied, thus suppressing performance degradation and increased manufacturing costs, and exhibiting hydrophobicity. Therefore, it is possible to guide the droplets in the nozzle flow path downstream and suppress icing in the nozzle flow path.

[0133]

[12] The cooling device of this disclosure is used to cool the cooling chamber of a refrigerated container. The cooling device includes a turbine that expands air drawn in from the cooling chamber. The cooling device operation method includes the following steps (SA): When the cooling device is started, the turbine is operated at a first speed until the inlet temperature of the turbine drops to less than a predetermined inlet side temperature. When the inlet temperature of the turbine is less than the predetermined inlet side temperature, the turbine is operated at a second speed greater than the first speed.

[0134] The method described in

[12] above achieves the same effect as described in [1] above.

[0135]

[13] The cooling device of this disclosure is used to cool the cooling chamber of a refrigerated container. The cooling device includes a turbine that expands air drawn in from the cooling chamber. The cooling device operation method includes the following steps (SB): When the cooling device is started, the turbine is operated at a first speed until the outlet temperature of the turbine drops to below a predetermined outlet temperature. When the outlet temperature of the turbine is below the predetermined outlet temperature, the turbine is operated at a second speed greater than the first speed.

[0136] The method described in

[13] above achieves the same effect as described in [2] above.

[0137]

[14] The cooling device of this disclosure is used to cool the cooling chamber of a refrigerated container. The cooling device includes a turbine that expands air drawn in from the cooling chamber. The cooling device operation method includes the following steps (SC): When the cooling device is started, the turbine is operated at a first speed until the outlet temperature of the turbine drops below a predetermined outlet temperature. When the outlet temperature of the turbine is below the predetermined outlet temperature, the turbine is operated at a second speed greater than the first speed, and the turbine is operated at the second speed until the inlet temperature of the turbine drops below a predetermined inlet temperature. When the inlet temperature of the turbine is below the predetermined inlet temperature, the turbine is operated at a third speed greater than the second speed.

[0138] The method described in

[14] above achieves the same effect as described in [3] above.

[0139] Explanation of reference numerals in the attached figures

[0140] 1. Cooling device

[0141] 1A Cooling device (first embodiment)

[0142] 1B Cooling device (Second embodiment)

[0143] 1C Cooling device (Third embodiment)

[0144] 2 turbos

[0145] 4. Control device

[0146] 6. Air lines

[0147] 8. Heat exchanger

[0148] 10 Compressors

[0149] 12 Air Cooler

[0150] 14 Electric motor

[0151] 15a drive shaft

[0152] 15b drive shaft

[0153] 16 Inlet Temperature Sensor

[0154] 17. Outlet temperature sensor

[0155] 20A Start-up and Operation Unit (First Embodiment)

[0156] 20B Start-up and Operation Unit (Second Embodiment)

[0157] 20C Start-up and Operation Unit (Third Embodiment)

[0158] 21. Shell

[0159] 22 Turbine Rotor

[0160] 23 Vortex Flow Path

[0161] 24 Vortex Flow Path Formation Section

[0162] 25 Nozzle Flow Path

[0163] 26 Nozzle flow path forming section

[0164] 30 Vortex Flow Road Surface

[0165] 32 Nozzle flow road surface

[0166] 35. Moving leaves

[0167] 36 Vortex Flow Channel

[0168] 38 Nozzle Flow Path Groove

[0169] 40 Nozzle blades

[0170] 42. Surface of nozzle blades

[0171] 45 Discharge flow path

[0172] 44 Discharge flow path forming part

[0173] 46 Exports

[0174] 100 refrigerated containers

[0175] 101 Cooling Chamber

[0176] 102 Main Body

[0177] 200 objects

[0178] 201 The surface of the object

[0179] 202 droplets

[0180] 203 The surface of the droplet

[0181] A1 Cooling Air

[0182] A2 draws in air.

[0183] D1 Axis Direction

[0184] D2 Radial

[0185] D3 Zhou Xiang

[0186] Da is the direction of airflow (vortex flow path).

[0187] Db: Direction of airflow (nozzle flow path)

[0188] L tangent

[0189] M hydrophobic layer

[0190] O axis

[0191] Point P1

[0192] PA Directive (First Implementation)

[0193] PB Second Implementation

[0194] PC Third Embodiment

[0195] T1 Inlet Temperature

[0196] T2 outlet temperature

[0197] TA inlet side specified temperature

[0198] TB outlet side specified temperature

[0199] W1 Width of the vortex flow channel

[0200] W2 width of nozzle flow path groove

[0201] X1 First speed (low speed)

[0202] X2 Second speed (medium speed)

[0203] X3 Third Speed ​​(High Speed)

[0204] SA First Start-up Operation Steps

[0205] SA1 Low-speed operation steps

[0206] SA2 Inlet Temperature Determination Steps

[0207] SA3 High-speed operation steps

[0208] SB Second Start-up Operation Steps

[0209] SB1 Low-speed operation procedure

[0210] SB2 Outlet Temperature Determination Procedure

[0211] SB3 High-Speed ​​Operation Steps

[0212] SC Third Start-up Operation Steps

[0213] SC1 Low-speed operation procedure

[0214] SC2 Outlet Temperature Determination Procedure

[0215] SC3 Medium Speed ​​Operation Procedure

[0216] SC4 Inlet Temperature Determination Procedure

[0217] SC5 High-speed operation procedure.

Claims

1. A cooling device for cooling the cooling compartment of a refrigerated container, the cooling device comprising: A turbine that expands the air drawn in from the cooling chamber; and The control device controls the operation of the turbine. The control device includes a start-up and operation unit. When the cooling device is started, the start-up and operation unit causes the turbine to run at a first speed until the inlet temperature of the turbine drops below a preset inlet side temperature. When the inlet temperature of the turbine is lower than the preset inlet side temperature, the start-up and operation unit causes the turbine to run at a second speed greater than the first speed.

2. A cooling device for cooling the cooling compartment of a refrigerated container, the cooling device comprising: A turbine that expands the air drawn in from the cooling chamber; and The control device controls the operation of the turbine. The control device includes a start-up and operation unit. When the cooling device is started, the start-up and operation unit causes the turbine to run at a first speed until the outlet temperature of the turbine drops to less than a preset outlet side specified temperature. When the outlet temperature of the turbine is less than the outlet side specified temperature, the start-up and operation unit causes the turbine to run at a second speed greater than the first speed.

3. A cooling device for cooling the cooling chamber of a refrigerated container, the cooling device comprising: A turbine that expands the air drawn in from the cooling chamber; and The control device controls the operation of the turbine. The control device includes a start-up and operation unit. When the cooling device is started, the start-up and operation unit causes the turbine to operate at a first speed until the outlet temperature of the turbine drops below a preset outlet side specified temperature. When the outlet temperature of the turbine is lower than the outlet side specified temperature, the start-up and operation unit causes the turbine to operate at a second speed greater than the first speed, and causes the turbine to operate at the second speed until the inlet temperature of the turbine drops below a preset inlet side specified temperature. When the inlet temperature of the turbine is lower than the inlet side specified temperature, the start-up and operation unit causes the turbine to operate at a third speed greater than the second speed.

4. The cooling device according to any one of claims 1 to 3, wherein, The turbine comprises: Turbine rotor; A vortex flow path forming section forms a vortex flow path on the outer periphery of the turbine rotor; and A nozzle flow path forming section forms a nozzle flow path for guiding air from the vortex flow path to the turbine rotor. The vortex flow path forming part and the nozzle flow path forming part are both hydrophobic.

5. The cooling device according to claim 4, wherein, The vortex flow path forming part and the nozzle flow path forming part are respectively made of aluminum alloy.

6. The cooling device according to claim 4, wherein, The vortex flow path forming part has a hydrophobic coating applied to the surface facing the vortex flow path. The nozzle flow path forming part has a hydrophobic coating applied to the surface facing the nozzle flow path.

7. The cooling device according to claim 4, wherein, The vortex flow path forming part has vortex flow path grooves formed on the surface facing the vortex flow path, extending along the flow direction of the air flowing in the vortex flow path. The width of the vortex flow channel is greater than 0.01 mm and less than 0.5 mm.

8. The cooling device according to claim 4, wherein, The nozzle flow path forming portion has a nozzle flow path groove formed on its surface facing the nozzle flow path, extending along the flow direction of the air flowing in the nozzle flow path. The width of the nozzle flow path groove is greater than 0.01 mm and less than 0.5 mm.

9. The cooling device according to claim 4, wherein, The turbine also includes a plurality of nozzle blades that are circumferentially spaced apart in the nozzle flow path of the turbine rotor. The nozzle blades have a hydrophobic coating on the surface facing the nozzle flow path, and no groove forming is performed on the surface facing the nozzle flow path.

10. The cooling device according to claim 9, wherein, The turbine rotor comprises multiple moving blades. The number of nozzle blades is less than the number of the plurality of moving blades.

11. The cooling device according to any one of claims 1 to 3, wherein, The turbine comprises: Turbine rotor; A vortex flow path forming section forms a vortex flow path on the outer peripheral side of the turbine rotor; A nozzle flow path forming section forms a nozzle flow path for guiding air from the vortex flow path to the turbine rotor; and Multiple nozzle blades are arranged at intervals in the nozzle flow path circumferentially on the turbine rotor. The nozzle flow path forming part is made of aluminum alloy. The nozzle flow path forming portion has a nozzle flow path groove with a width of 0.01 mm or more and 0.5 mm or less, extending along the flow direction of the air flowing in the nozzle flow path, formed on the surface facing the nozzle flow path, and a hydrophobic coating treatment is applied to the surface facing the nozzle flow path. The nozzle blades have a hydrophobic coating on the surface facing the nozzle flow path, and no groove forming is performed on the surface facing the nozzle flow path.

12. A method of operating a cooling device for cooling a cooling chamber of a refrigerated container, the cooling device comprising a turbine for expanding air drawn in from the cooling chamber, the method of operating the cooling device comprising the following steps: When the cooling device is started, the turbine is operated at a first speed until the inlet temperature of the turbine drops below a predetermined inlet side temperature. When the inlet temperature of the turbine is below the predetermined inlet side temperature, the turbine is operated at a second speed greater than the first speed.

13. A method of operating a cooling device for cooling a cooling chamber of a refrigerated container, the cooling device comprising a turbine for expanding air drawn in from the cooling chamber, the method of operating the cooling device comprising the following steps: When the cooling device is started, the turbine is operated at a first speed until the outlet temperature of the turbine drops to less than a predetermined outlet temperature. When the outlet temperature of the turbine is less than the predetermined outlet temperature, the turbine is operated at a second speed greater than the first speed.

14. A method of operating a cooling device for cooling a cooling chamber of a refrigerated container, the cooling device comprising a turbine for expanding air drawn in from the cooling chamber, the method of operating the cooling device comprising the following steps: When the cooling device is started, the turbine is operated at a first speed until the outlet temperature of the turbine drops below a preset outlet temperature. When the outlet temperature of the turbine is lower than the preset outlet temperature, the turbine is operated at a second speed greater than the first speed, and the turbine is operated at the second speed until the inlet temperature of the turbine drops below a preset inlet temperature. When the inlet temperature of the turbine is lower than the preset inlet temperature, the turbine is operated at a third speed greater than the second speed.

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