Cooling system for mobile body, mobile body with cooling system, and cooling control method

Abstract

The present application aims to establish an efficient and stable cooling cycle. A cooling system for a moving body includes a compressor, a condenser, an expansion valve, an evaporator, a flow rate adjustment device that adjusts a flow rate of a cooling fluid that is guided to the condenser depending on an external environment of the moving body, an ambient temperature acquisition sensor that detects an ambient condition for acquiring an ambient temperature to which the condenser is exposed by the cooling fluid, a pressure sensor that detects a pressure of refrigerant in the condenser, a temperature sensor that detects a temperature of the refrigerant on a downstream side of the condenser, and a control unit that executes a first process of adjusting the flow rate of the cooling fluid so that the pressure of the refrigerant in the condenser is greater than a saturation pressure of the refrigerant at the ambient temperature based on an output of the ambient temperature acquisition sensor and the pressure sensor, and a second process of adjusting an opening degree of the expansion valve so that the refrigerant on the downstream side of the condenser is in a supercooled state based on an output of the pressure sensor and an output of the temperature sensor.

Description

Technical Field

[0001] This disclosure relates to techniques for cooling mobile bodies. Background Technology

[0002] Patent Document 1 describes a vehicle air conditioning system that determines the degree of refrigerant subcooling at the refrigerant inlet side of the expansion valve. If the system determines that the refrigerant is not subcooled, it prioritizes increasing the airflow to the cooling fan of the outdoor heat exchanger rather than increasing the discharge volume of the electric compressor. Furthermore, it discloses suppressing the upper limit speed of the cooling fan when the refrigerant pressure on the high-pressure side of the refrigeration cycle unit decreases.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2013-154753 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, in the technology disclosed in Patent Document 1, the upper limit speed of the cooling fan is suppressed to a low level based on the refrigerant pressure on the high-pressure side, thus potentially preventing subcooling. Furthermore, it cannot be guaranteed that the refrigerant near the exterior heat exchanger is in a gaseous phase with a temperature higher than the outside air temperature. Under these circumstances, the latent heat area in the exterior heat exchanger cannot be utilized to the maximum extent, potentially preventing the establishment of an efficient and stable cooling cycle.

[0008] Therefore, the purpose of this disclosure is to enable an efficient and stable cooling cycle when cooling a moving body.

[0009] Technical solutions for solving the problem

[0010] To address the aforementioned issues, a cooling system for a mobile body is provided, comprising: a compressor for compressing a refrigerant; a condenser for condensing the refrigerant compressed by the compressor; an expansion valve for expanding the refrigerant condensed by the condenser; an evaporator for evaporating the refrigerant expanded by the expansion valve to cool fluid within the mobile body; a flow rate adjustment device for adjusting the flow rate of the cooling fluid, which depends on the external environment of the mobile body, as it is guided to the condenser; an ambient temperature sensor for detecting environmental conditions that allow the condenser to be exposed to the ambient temperature by the cooling fluid; and a pressure sensor for detecting the temperature of the refrigerant. The system includes: a pressure of refrigerant in a condenser; a temperature sensor that detects the temperature of the refrigerant downstream of the condenser; and a control unit that performs a first process and a second process. The first process involves adjusting the flow rate of the cooling fluid using a flow adjustment device based on the ambient temperature obtained from the output of a sensor and the output of the pressure sensor, so that the pressure of the refrigerant in the condenser is greater than the saturation pressure of the refrigerant at the ambient temperature. The second process involves adjusting the opening of the expansion valve based on the output of the pressure sensor and the output of the temperature sensor, so that the refrigerant downstream of the condenser is in a subcooled state.

[0011] According to the cooling system for this mobile body, a first process and a second process are performed. The first process involves adjusting the flow rate of the cooling fluid using a flow regulating device to make the pressure of the refrigerant in the condenser greater than the saturation pressure of the refrigerant at ambient temperature. The second process involves adjusting the opening of the expansion valve to make the refrigerant in a subcooled state on the downstream side of the condenser. Therefore, the latent heat region in the condenser can be effectively utilized, enabling a highly efficient and stable cooling cycle.

[0012] In addition, the mobile body with a cooling system includes: the aforementioned cooling system for mobile bodies; and a mobile body capable of moving in a state in which the cooling system for mobile bodies is assembled.

[0013] Therefore, an efficient and stable cooling cycle can be established in the moving body.

[0014] Additionally, the cooling control method is a cooling control method for controlling a cooling system in which refrigerant circulates in a compressor, condenser, expansion valve, and evaporator within a moving body. The method includes: a first process, adjusting the flow rate of the cooling fluid directed to the condenser based on the ambient temperature exposed to the condenser and the pressure of the refrigerant in the condenser, such that the pressure of the refrigerant in the condenser is greater than the saturation pressure of the refrigerant at the ambient temperature; and a second process, adjusting the opening of the expansion valve based on the pressure of the refrigerant in the condenser and the temperature of the refrigerant downstream of the condenser, such that the refrigerant downstream of the condenser is in a subcooled state.

[0015] According to this cooling control method, a first process and a second process are performed. The first process involves adjusting the flow rate of the cooling fluid guided to the condenser so that the pressure of the refrigerant in the condenser is greater than the saturation pressure of the refrigerant at the ambient temperature. The second process involves adjusting the opening of the expansion valve so that the refrigerant on the downstream side of the condenser is in a subcooled state. Therefore, the latent heat region in the condenser can be effectively utilized, enabling a highly efficient and stable cooling cycle.

[0016] Invention Effects

[0017] When cooling the moving body, an efficient and stable cooling cycle can be established. Attached Figure Description

[0018] Figure 1 This is a schematic diagram showing a movable body with a cooling system according to the embodiment.

[0019] Figure 2 This is a block diagram representing the cooling system.

[0020] Figure 3 This is a flowchart illustrating an example of a process performed by the control unit.

[0021] Figure 4 It is a graph that represents the data flow in the system.

[0022] Figure 5 It is a pressure-enthalpy curve of the system.

[0023] Figure 6 This is a block diagram representing the cooling system for the moving body involved in the modified example.

[0024] Figure 7 This is a flowchart illustrating an example of the fourth process performed by the control unit involved in the modified example.

[0025] Figure 8 This is a schematic diagram of a moving body with a cooling system involved in a modified example.

[0026] Figure 9 This is a schematic diagram showing other moving bodies with cooling systems involved in the variations. Detailed Implementation

[0027] The following describes the cooling system for the mobile body, the mobile body with the cooling system, and the cooling control method according to the embodiments.

[0028] Figure 1 This is a schematic diagram of a mobile body 10 equipped with a cooling system, including a mobile body cooling system 20 and a mobile body 12.

[0029] The mobile body 12 is a device for moving in space. The mobile body 12 includes a propulsion device 13 and a main body 14 on which the propulsion device 13 is assembled. The propulsion device 13 is a device that generates propulsive force for movement. The main body 14 has an outer shell that separates internal compartments such as equipment rooms, luggage compartments, and living quarters from the outside. The propulsion device 13 is assembled to the main body 14, and the mobile body 12 can move within space using the propulsive force of the propulsion device 13. The space to which it is moved can be on the ground, in the atmosphere, underwater, etc.

[0030] In this embodiment, such as Figure 1 As shown, the explanation will primarily focus on the case where the moving body 12 is an aircraft 12. In this embodiment, the main body 14 is an airframe including the fuselage, main wing, tail, etc. Even for an aircraft, various variations are envisioned, such as the absence of a tail or the absence of a dividing line between the fuselage and the main wing. Furthermore, the propulsion device 13 can utilize a jet engine, a propeller rotated by a prime mover, or a propulsion device utilizing a motor, etc. The propulsion device 13 may also be assembled to the main wing. In addition to an aircraft 12, the moving body 12 may also be a water-borne propulsion vehicle, a railway vehicle (e.g., a railway vehicle that travels at high speeds (e.g., 400 km / h or higher), such as a maglev railway, etc.

[0031] A cooling system 20 is assembled on the aircraft 12. The cooling system 20 is a type of VCS (Vapor Cycle System). In the aircraft 12, an external airflow path is formed that draws in outside air A1 into the main body 14, exchanges heat with the cooling system 20, and then exhausts it to the outside. Outside air A1 is an example of a cooling fluid used to release heat from the cooling system 20 to fluids other than those exposed to the object being cooled within the aircraft body. Outside air A1 can also be drawn into the main body 14 via the fuselage, main wing, jet engine, etc. Thus, the cooling system 20 can exhaust heat to the outside. Inside the main body 14, a device 16 is provided as the object being cooled. In the aircraft 12, an internal airflow path is formed that guides internal cooling air A2, cooled by the cooling system 20, to the device 16, returns it to the cooling system 20 for further cooling, and then returns the internal cooling air A2 back to the device 16. The device 16 is cooled by being exposed to the internal cooling air A2.

[0032] Furthermore, there may be cases where the cooling fluid is a fluid other than air, such as a liquid. For example, as explained in the later variations, consider a water-propelled body that propels itself in water, where the cooling system 20 is cooled using a liquid outside the water-propelled body. There may also be cases where the fluid exposed to the object being cooled within the machine body is a fluid other than air, such as a liquid. For example, consider using a coolant cooled by the evaporator 28 to cool the object within the machine body.

[0033] Device 16 can be a control device such as a computer, a power supply device such as a battery or power circuit, or a mechanical device. The object to be cooled may not be device 16; it can also be cargo in the luggage compartment or air in the living room.

[0034] In aircraft 12, the external environment varies considerably depending on airspeed and altitude. The cooling system 20 draws in outside air and uses a condenser for heat exchange. Therefore, large variations in the external environment can significantly impact the heat exchange performance of the cooling system 20. The cooling system 20 of this embodiment relates to a technique that enables an efficient and stable cooling cycle to be established regardless of large variations in the external environment.

[0035] Figure 2 This is a block diagram representing the cooling system 20.

[0036] First, focusing on the structure related to the refrigerant cycle, the cooling system 20 includes a compressor 22, a condenser 24, an expansion valve 26, and an evaporator 28.

[0037] Compressor 22 draws in refrigerant evaporated by evaporator 28, compresses the refrigerant, and discharges it to condenser 24. Compressor 22 may have, for example, a motor, a rotor or blades driven by the motor, which compresses the refrigerant. The compression capacity of the refrigerant in compressor 22 is controlled by controlling the motor speed. For example, increasing the motor speed increases the compression ratio, and the refrigerant is compressed to a higher pressure. Compressor 22 can be any type capable of compressing refrigerant; it can be a centrifugal compressor or a positive displacement compressor. The amount of refrigerant circulating in the cycle depends on the discharge pressure and discharge flow rate of compressor 22, which are determined by the compressor speed. Furthermore, the refrigerant flow rate is varied within the performance range of compressor 22 at this speed by opening and closing expansion valve 26 (described later).

[0038] The condenser 24 condenses and liquefies the refrigerant delivered from the compressor 22. The liquefied refrigerant is then discharged to the expansion valve by the driving force of the cycle generated by the compressor 22. Here, the condenser 24 is exposed to the outside air A1 that is drawn into the moving body 12 via the outside airflow path B1. As a result, heat exchange occurs between the refrigerant in the condenser 24 and the outside air A1, the refrigerant condenses and liquefies, and the outside air A1 is heated and released to the outside. The greater the flow of outside air A1 through the condenser 24, the greater the heat exchange in the condenser 24. In addition, the lower the temperature of the outside air A1, the greater the heat exchange in the condenser 24. The temperature of the outside air A1 depends on the external environment and is difficult to control itself; therefore, the amount of heat exchange in the condenser 24 can be adjusted by regulating the flow rate of the outside air A1 through the condenser 24. For example, a flow regulating valve 30 can be installed on the outside airflow path B1. The flow regulating valve 30 is a valve that adjusts the flow rate of outside air A1 guided to the condenser 24 by adjusting the flow of outside air A1 in the outside airflow path B1. The flow regulating valve 30 can be, for example, a device that adjusts the flow or flow rate of outside air A1 by actuating the valve or vane via a solenoid, motor, or other drive unit, such as a butterfly valve or damper. In addition to or instead of the flow regulating valve 30, a motor 31a and a fan 31b may be provided to increase the airflow in the outside airflow path B1. The flow regulating valve 30, motor 31a, and fan 31b can be provided upstream or downstream of the condenser 24 in the flow of outside air A1. The flow regulating valve 30, motor 31a, and fan 31b are examples of flow regulating devices that adjust the flow rate of cooling air, which depends on the external environment within the moving body 12, when it is guided to the condenser 24. The following description focuses on an example where the flow rate of outside air A1, which is used for cooling, is adjusted by indicating the opening degree of the flow regulating valve 30.

[0039] Expansion valve 26 expands the refrigerant supplied from condenser 24. The expanded refrigerant is then delivered to evaporator 28 by the driving force of a cycle generated by compressor 22. Expansion valve 26 is configured to adjust its opening degree. For example, expansion valve 26 may also have a structure in which the valve body is moved by a drive unit such as a stepper motor to adjust the opening degree. The larger the opening degree of expansion valve 26, the lower the refrigerant pressure in condenser 24 and the higher the refrigerant pressure in evaporator, and the smaller the expansion ratio. Conversely, the smaller the opening degree of expansion valve, the higher the refrigerant pressure in condenser 24 and the lower the refrigerant pressure in evaporator, and the larger the expansion ratio.

[0040] The evaporator 28 cools the air inside the moving body 12 by evaporating the refrigerant expanded by the expansion valve 26. Specifically, the internal cooling air A2 in the internal airflow path B2 within the moving body 12 circulates via the peripheral space of the device 16 (which is being cooled) and the peripheral space of the evaporator 28. By exposing the evaporator 28 to the internal cooling air A2, heat exchange occurs between the refrigerant within the evaporator 28 and the internal cooling air A2, cooling the internal cooling air A2 and heating the refrigerant to evaporate. The greater the airflow of the internal cooling air A2 through the evaporator 28, the greater the heat exchange in the evaporator 28. Furthermore, the higher the temperature of the internal cooling air A2, the greater the heat exchange in the evaporator 28. The temperature of the internal cooling air A2 depends primarily on the temperature of the device 16, and the amount of heat exchange in the evaporator 28 can also be adjusted by regulating the flow rate of the internal cooling air A2 through the evaporator 28. For example, a motor 34a and a fan 34b for increasing the airflow speed or volume can be installed in the internal airflow path B2. In addition to motor 34a and fan 34b, or alternatives to motor 34a and fan 34b, a flow regulating valve may also be provided. The flow regulating valve, motor 34a, and fan 34b may be located upstream of the condenser 24 or downstream of the flow of outside air A1.

[0041] These components are connected via piping, in which the refrigerant circulates sequentially in the compressor 22, condenser 24, expansion valve 26, and evaporator 28.

[0042] Alternatively, a gas-liquid separator 21 can be installed between the evaporator 28 and the compressor 22. The gas-liquid separator 21 is a liquid separator that separates the liquid refrigerant that fails to evaporate from the gaseous refrigerant after evaporation by the evaporator 28.

[0043] In this cooling system 20, sensors are provided to detect the state of the refrigerant at various points, as described below. Specifically, a first pressure sensor 40 and a second pressure sensor 41 are provided as pressure sensors for detecting the pressure in the condenser 24. The first pressure sensor 40 is provided at the upstream inlet of the condenser 24 to detect the pressure of the refrigerant at that inlet. The second pressure sensor 41 is provided at the downstream outlet of the condenser 24 to detect the pressure of the refrigerant at that outlet. Furthermore, only one sensor can be used to detect the pressure in the condenser 24. For example, only one of the first pressure sensor 40 and the second pressure sensor 41 may be provided. By providing the first pressure sensor 40 and the second pressure sensor 41 upstream and downstream of the condenser 24 respectively, cooling processing that takes into account pressure loss in the condenser 24 can be performed. Moreover, a temperature sensor 42 is provided on the downstream piping of the condenser 24 to detect the temperature of the refrigerant downstream of the condenser 24.

[0044] Furthermore, the cooling system 20 is equipped with a cooling temperature detection sensor 43 that detects the cooling temperature based on the evaporator 28. The cooling temperature is the temperature that can be cooled by the internal cooling air A2 after being cooled by the evaporator 28. The cooling temperature detection sensor 43 is provided, for example, downstream of the evaporator 28 in the flow of the internal cooling air A2, at a position for detecting the temperature after being cooled by the evaporator 28.

[0045] Additionally, the cooling system 20 includes ambient temperature sensors 45 and 46 for acquiring ambient temperature. Ambient temperature refers to the ambient temperature at which the condenser 24 is exposed to the cooling air A1. When the surface ambient temperature of the moving body 12 is affected by at least one of the moving speed of the moving body 12 and the accompanying height (either height or depth), the ambient temperature can also be understood as the temperature influenced by the external environment taking into account at least one of the moving body 12's movement (speed) and height (either height or depth).

[0046] When the moving body 12 is an aircraft 12, the ambient temperature can also be the total temperature (outer air total temperature) of the aircraft 12. The total temperature is the temperature obtained by adding the static temperature and the dynamic temperature of the kinetic energy component; it is affected by both the speed and altitude of the aircraft 12. The cooling air A1 is the outside air A1 guided from outside the aircraft 12 to the cooling system 20, and therefore has a temperature corresponding to the total temperature of the aircraft 12. More specifically, the total temperature refers to the temperature of the fluid (in this case, air) on the outer surface of the aircraft 12, also known as the stagnation temperature. For example, the total temperature can be calculated based on the aircraft's speed, altitude, etc. Therefore, as ambient temperature acquisition sensors 45 and 46, an airspeed sensor and an altimeter can also be installed, and the total temperature as the ambient temperature can be derived from the outputs of these ambient temperature acquisition sensors 45 and 46. Alternatively, a temperature sensor that detects the temperature outside the aircraft 12 can be installed, and the total temperature can be calculated from the output of this temperature sensor. Furthermore, the external ambient temperature can also be the temperature obtained by directly measuring the outside air A1 flowing into the cooling system 20.

[0047] The structure involved in controlling the cooling system 20 will be described. The cooling system 20 includes a control unit 50 for controlling various components.

[0048] The control unit 50 is a computer equipped with a processor 52 (such as a CPU, Central Processing Unit), a storage unit 54, etc. An input unit 58, such as a keyboard or touch panel, for inputting various commands and settings may also be connected to the control unit 50. The processor 52 is composed of circuitry and performs arithmetic processing according to the steps described in the program 54a stored in the storage unit 54, executing various processes to control the drive of the compressor 22, flow regulating valve 30, expansion valve 26, etc. The processor 52 can be a single processor or multiple processors. The storage unit 54 is a non-volatile storage device such as an HDD (Hard disk drive) or SSD (Solid-state drive). The storage unit 54 stores the program 54a, target cooling temperature 54b, pressure deviation value 54c, subcooling setting value 54d, saturation pressure gauge 54e, saturation temperature gauge 54f, etc. The program 54a is a program used to cause the control unit 50, which is a computer, to execute the processes involved in the system 20. The program can be recorded and circulated on a portable recording medium, or it can be provided via a communication medium such as a communication network. The target cooling temperature 54b is the target temperature at which the internal cooling air A2 is cooled by the evaporator 28. The compressor 22 is driven in such a way that the detected temperature of the internal cooling air A2, based on the output of the temperature sensor 42, becomes this target temperature. The saturation pressure gauge 54e is a table that establishes a correspondence between saturation pressure and refrigerant temperature. The saturation pressure of the refrigerant corresponding to the total temperature is calculated by referring to the derived total temperature and the saturation pressure gauge 54e. The pressure deviation value 54c is a target value that causes the inlet pressure of the condenser 24 to deviate from the saturation pressure corresponding to the total temperature. The flow regulating valve 30 is driven in such a way that the detected pressure, based on the output of the first pressure sensor 40, becomes the target value by which the pressure deviation value 54c is deviated from the saturation pressure relative to the total temperature. The saturation temperature gauge 54f is a table that establishes a correspondence between saturation temperature and refrigerant pressure. The saturation temperature of the refrigerant relative to the detected pressure is calculated based on the pressure output by the second pressure sensor 41 and the saturation temperature gauge 54f. The subcooling setpoint 54d is the target subcooling at the outlet of condenser 24. The subcooling is calculated based on the difference between the saturation temperature relative to the detected pressure based on the output of the second pressure sensor 41 and the detected temperature based on the output of the temperature sensor 42. The opening of the expansion valve 26 is then controlled to achieve this subcooling setpoint 54d. The pressure deviation value 54c and the subcooling setpoint 54d can be values ​​set based on inference, experimentation, or experience.

[0049] Figure 3 This is a flowchart illustrating an example of the processing performed by the control unit 50.

[0050] Steps S1 to S8 represent the first process, steps S11 to S17 represent the second process, and steps S21 to S25 represent the third process. In this embodiment, an example is shown where a control unit 50, physically configured as a computer, performs the first and second processes, and also performs the third process. Physically configured as a computer means a device capable of processing as a single unit. Therefore, the processor 52 within the control unit 50 can also be configured as a multi-core CPU. The first, second, and third processes can also be processed in parallel. This parallel processing includes not only the case where multiple core processors assembled in the processor 52 process the data separately, but also the case where one or more core processors simulate parallel processing. Of course, the first, second, and third processes can also be processed by physically different computers.

[0051] The first process is as follows: based on the total ambient temperature obtained by sensors 45 and 46 (which are based on ambient temperature), and the output of the first pressure sensor 40, the flow rate is adjusted by a flow regulating valve 30 (which is an example of a flow regulating device) so that the pressure of the refrigerant in the condenser 24 is greater than the saturation pressure of the refrigerant at the ambient temperature.

[0052] That is, in step S1, the total temperature is calculated. As described above, for example, the total temperature is calculated based on the aircraft's airspeed sensor, altimeter, etc., which are used as sensors 45 and 46 to obtain ambient temperature.

[0053] In the next step S2, the saturation pressure relative to the total temperature is determined by referring to the saturation pressure table 54e, based on the total temperature obtained in step S1.

[0054] In the next step S3, the saturation pressure relative to the total temperature obtained in step S2 is added to the pressure deviation value 54c to obtain the target pressure Pt. Furthermore, the pressure deviation value 54c can be any value greater than 0.

[0055] In the next step S4, the detected pressure P based on the output of the first pressure sensor 40 is compared with the target pressure Pt. If the detected pressure P is less than the target pressure Pt, proceed to step S5, and reduce the opening of the flow regulating valve 30. As a result, the heat exchange of the refrigerant in the condenser 24 decreases, and the detected pressure P rises and approaches the target pressure Pt. If the detected pressure P is the same as the target pressure Pt, proceed to step S6, and maintain the opening of the flow regulating valve 30. As a result, the state where the detected pressure P and the target pressure Pt are the same is maintained. If the detected pressure P is greater than the target pressure Pt, proceed to step S7, and increase the opening of the flow regulating valve 30. As a result, the heat exchange of the refrigerant in the condenser 24 increases, and the detected pressure P decreases and approaches the target pressure Pt.

[0056] Through steps S4 to S7, a process is performed to make the refrigerant pressure at the inlet of condenser 24 reach or exceed the saturation pressure relative to the total temperature, thus making the refrigerant at the inlet a gaseous phase. Here, the temperature of the refrigerant at the inlet reaches or exceeds the total temperature of the outside gas A1. That is, steps S4 to S7 are an example of the following process: comparing the aforementioned saturation pressure with the aforementioned refrigerant pressure, and adjusting the flow rate based on the flow adjustment device according to the comparison result so that the refrigerant upstream of condenser 24 reaches a gaseous phase with a temperature exceeding or exceeding the total temperature of the outside gas A1.

[0057] After steps S5, S6, and S7, the process proceeds to step S8. In step S8, it is determined whether cooling has ended, for example, by determining whether a power-on / off command has been issued for the system 20. For example, if it is determined that cooling has not ended and continues based on a power-on / off signal based on an operation such as a power switch, the process returns to step S1 and repeats the subsequent processing. When it is determined that cooling has ended, the first process ends.

[0058] The second process is as follows: Based on the output of the second pressure sensor 41 and the output of the temperature sensor 42, the opening of the expansion valve 26 is adjusted so that the refrigerant on the downstream side of the condenser 24 becomes subcooled.

[0059] That is, in step S11, the saturation temperature at the refrigerant pressure is determined based on the refrigerant pressure and saturation temperature table 54f on the downstream side of the condenser 24 based on the output of the second pressure sensor 41.

[0060] In the next step S12, the subcooling S is obtained by subtracting the refrigerant temperature on the downstream side of the condenser 24 based on the output of the temperature sensor 42 from the saturation temperature obtained in step S11.

[0061] In the next step S13, the subcooling target value St, defined as the subcooling setpoint 54d, is compared with the subcooling S. Furthermore, the subcooling target value St can be any value representing the establishment of subcooling. If the subcooling S is greater than the subcooling target value St, the process proceeds to step S14, increasing the opening of the expansion valve 26. This increases the flow rate in the condenser 24. Here, if the temperature and flow rate of the outside air A1, and the temperature of the refrigerant in the condenser 24, are constant, the heat exchange in the condenser 24 is constant. Under this condition, if the flow rate in the condenser 24 increases, the downstream temperature of the condenser rises accordingly. Thus, the subcooling S decreases and approaches the subcooling target value St. If the subcooling S is the same as the subcooling target value St, the process proceeds to step S15, maintaining the opening of the expansion valve 26. This maintains the state where the subcooling S is the same as the subcooling target value St. If the subcooling S is less than the target subcooling value St, proceed to step S16 and reduce the opening of the expansion valve 26. As a result, the flow rate in the condenser 24 decreases. Consequently, as described above, under the condition of constant heat exchange, corresponding to the decrease in the flow rate in the condenser 24, the downstream temperature of the condenser decreases, and the subcooling S increases, approaching the target subcooling value St.

[0062] Steps S13 to S16 are performed to make the subcooling S at the outlet of condenser 24 reach the target subcooling value St, i.e., the subcooled state. That is, steps S13 to S16 are an example of the following process: the above-mentioned saturation temperature is compared with the above-mentioned refrigerant temperature, and the opening of expansion valve 26 is adjusted according to the comparison result so that the refrigerant on the downstream side of condenser 24 is in a subcooled state.

[0063] After steps S14, S15, and S16, proceed to step S17. In step S17, it is determined whether cooling has ended, for example, by determining whether a power-on / off command for the system 20 has been issued. If it is determined that cooling has not ended and continues, return to step S11 and repeat the subsequent processing. When it is determined that cooling has ended, the second process ends.

[0064] The third process is to control the compressor 22 based on the cooling temperature output by the cooling temperature detection sensor 43 and the target cooling temperature 54b.

[0065] That is, in step S21, the cooling temperature T based on the output of the cooling temperature detection sensor 43, i.e., the temperature T of the internal cooling air A2 downstream of the evaporator 28, is compared with the target cooling temperature Ta specified by the target cooling temperature 54b. If the temperature T is less than the target cooling temperature Ta, the process proceeds to step S22, where the speed of the compressor 22 is reduced. As a result, the compression ratio of the refrigerant before and after the compressor 22 decreases, the refrigerant pressure in the evaporator 28 increases, and the refrigerant temperature rises. Therefore, the temperature difference between the internal cooling air A2 and the refrigerant in the evaporator 28 decreases, the heat exchange decreases, and the temperature T rises, approaching the target cooling temperature Ta. In addition, when the speed of the compressor 22 is reduced, the refrigerant circulation flow rate also decreases, which also reduces the heat exchange in the evaporator 28, thus also having the effect of increasing the temperature T. If the temperature T is the same as the target cooling temperature Ta, the process proceeds to step S23, where the speed of the compressor 22 is maintained. This maintains the state where the temperature T is the same as the target cooling temperature Ta. If the temperature T is greater than the target cooling temperature Ta, the process proceeds to step S24, where the speed of the compressor 22 is increased. As a result, the compression ratio of the refrigerant before and after compressor 22 increases, the refrigerant pressure in evaporator 28 decreases, and the refrigerant temperature decreases. Consequently, the temperature difference between the internal cooling air A2 and the refrigerant in evaporator 28 increases, and the cooling capacity of system 20 improves. Therefore, temperature T decreases, approaching the target cooling temperature Ta. The increased rotational speed of compressor 22 also increases the circulation flow rate, which further increases the heat exchange in evaporator 28, thus also contributing to a reduction in temperature T.

[0066] Steps S21 to S24 are an example of adjusting the speed of compressor 22 so that the temperature T of the internal cooling air A2 downstream of evaporator 28, i.e. the cooling temperature T, is close to the target cooling temperature Ta.

[0067] After steps S22, S23, and S24, proceed to step S25. In step S25, it is determined whether cooling continues, for example, whether there is a power-on / off command for system 20. If it is determined that cooling will not end and continues, return to step S21 and repeat the subsequent processing. When it is determined that cooling has ended, this third process ends.

[0068] In steps S8, S17, and S25, when it is determined that the cooling process has ended, the processing in system 20 ends.

[0069] Figure 4 This is a diagram representing the data flow in system 20. Figure 5 This is the pressure-enthalpy diagram of system 20. Referring to these diagrams, the data processing examples and refrigerant status for each part will be explained.

[0070] The refrigerant compressed in compressor 22 is fed into condenser 24. At this time, the first process described above is performed. That is, the total outside air temperature is calculated based on the aircraft speed, altitude, etc. of aircraft 12, and the saturation pressure is calculated based on the total outside air temperature and saturation pressure gauge 54e. The sum of the saturation pressure and the deviation value, along with the refrigerant pressure at the inlet of condenser 24, is provided to the controller (PIC02) implemented by the processing function of control unit 50. The controller (PIC02) provides the flow control valve 30 with a value indicating the opening degree of the flow control valve based on this summed value and the refrigerant pressure value. By adjusting the opening degree of flow control valve 30, the heat exchange rate of condenser 24 based on outside air A1 is adjusted so that the refrigerant pressure at the inlet of condenser 24 is greater than the saturation pressure relative to the cooling temperature of outside air A1, i.e., the total outside air temperature. Thus, the flow control device is controlled so that the refrigerant at the inlet of condenser 24 becomes a gas phase with a temperature higher than the total outside air A1.

[0071] In condenser 24, after heat exchange between the refrigerant and the outside gas A1, the refrigerant is sent to expansion valve 26. Furthermore, as described above, at the inlet of condenser 24, the refrigerant is in a gas phase with a temperature higher than the total temperature of the outside gas A1; therefore, the heat of the refrigerant is more reliably discharged to the outside gas A1 in condenser 24. When the refrigerant flows downstream of condenser 24, the second process described above is performed. That is, the saturation temperature is determined based on the refrigerant pressure and saturation temperature at the outlet of condenser 24. The subcooling, obtained by subtracting the refrigerant temperature downstream of condenser 24 from this saturation temperature, is provided to the controller (TIC03) implemented by the processing function of control unit 50. The controller (TIC03) provides the expansion valve 26 with a value indicating the opening degree of the expansion valve based on the subcooling and the subcooling setpoint. By adjusting the opening of the expansion valve 26, the pressure in the condenser 24 is adjusted, thereby adjusting the degree of expansion of the refrigerant in the expansion valve 26, so that the desired subcooling state corresponding to the subcooling set value is achieved at the outlet of the condenser 24.

[0072] The refrigerant is expanded through expansion valve 26. The refrigerant, now under reduced pressure, is then sent to evaporator 28. In evaporator 28, heat exchange occurs between the refrigerant and the internal cooling air A2, and the refrigerant becomes a gaseous phase. At the outlet of evaporator 28, the refrigerant may also be in a superheated state. Examples of methods to more reliably heat the refrigerant will be explained in later variations.

[0073] Refrigerant is fed from evaporator 28 to compressor 22 via gas-liquid separator 21. After being compressed in compressor 22, the refrigerant is fed again to condenser 24. The third process described above is performed when the refrigerant is sent from evaporator 28 to compressor 22. That is, the cooling temperature and target cooling temperature of the internal cooling air A2 after being cooled by evaporator 28 are provided to the controller (TIC01) implemented through the processing function. The controller (TIC01) provides the compressor 22 with a value indicating the rotational speed of compressor 22 based on the cooling temperature and target cooling temperature. The higher the compression ratio of compressor 22 according to the rotational speed command, the greater the cooling capacity of system 20, and the lower the cooling temperature of internal cooling air A2. By controlling the compression ratio of compressor 22 through its rotational speed, the cooling temperature can be adjusted to achieve the target cooling temperature.

[0074] According to the mobile body cooling system 20, the mobile body 10 with the cooling system, and the cooling control method configured as described above, a first process and a second process are performed. The first process is to adjust the flow rate based on the flow adjustment device so that the pressure of the refrigerant in the condenser 24 is greater than the saturation pressure of the refrigerant at ambient temperature. The second process is to adjust the opening based on the expansion valve 26 so that the refrigerant is in a subcooled state on the downstream side of the condenser 24. Therefore, on the upstream side of the condenser 24, the refrigerant becomes a gas phase with a temperature higher than the total temperature of the outside air A1, and on the downstream side of the condenser 24, the refrigerant is in a subcooled state. This allows for the effective utilization of the latent heat region of the refrigerant in the condenser 24, enabling an efficient and stable cooling cycle. Furthermore, this results in a high COP (Coefficient of Performance). For example, for mobile bodies with limited equipment weight and volume, such as aircraft, there is a significant advantage in maximizing the effective utilization of the performance of the system 20.

[0075] Furthermore, since the first and second processes described above are controlled independently of the heat exchange process in the evaporator 28, it is possible to avoid affecting the cooling performance of the object being cooled.

[0076] As a specific example, in the first process, by comparing the saturation pressure of the refrigerant relative to the ambient temperature with the detected pressure of the refrigerant in the condenser 24, the flow rate based on the flow adjustment device can be adjusted so that the pressure of the refrigerant in the condenser 24 is greater than the saturation pressure of the refrigerant at the ambient temperature. This process of making the pressure of the refrigerant in the condenser 24 greater than the saturation pressure of the refrigerant at the ambient temperature can also be understood as making the temperature of the refrigerant in the condenser 24, particularly at the inlet of the condenser 24, above the total temperature of the outside air.

[0077] In addition, as a specific example, in the second process, the saturation temperature of the refrigerant at the detection pressure relative to the downstream side of the condenser 24 and the detection temperature of the refrigerant at the downstream side of the condenser 24 can be compared, and the opening of the expansion valve 26 can be adjusted according to the results, so that the refrigerant at the downstream side of the condenser 24 becomes subcooled.

[0078] Furthermore, the control unit 50 performs a third process to control the compressor 22 based on the output of the cooling temperature detection sensor 43 and the target cooling temperature. Therefore, in the cooling cycle, the dryness at the evaporator inlet decreases, increasing the latent heat area in the evaporator 28 and thus increasing the cooling capacity. Therefore, through the aforementioned first and second processes, an efficient and stable cooling cycle can be established, and the cooling capacity of the system 20 can be adjusted according to the target cooling temperature.

[0079] Furthermore, in the mobile body 12 such as the aircraft 12, when outside air A1 is taken in to cool the condenser 24, the outside air A1 is at a temperature corresponding to the total temperature. Therefore, by using the total temperature as the ambient temperature, the first process can be performed based on an appropriate temperature, which is the temperature at which the condenser 24 is exposed.

[0080] Furthermore, by employing a structure that adjusts the flow rate through at least one of the flow adjustment valve 30 and the fan 31b as a flow adjustment device, the heat exchange rate in the condenser 24 can be adjusted.

[0081] Furthermore, by having the first and second processes implemented by a single physical computer, the structure is simplified.

[0082] Figure 6 This is a block diagram illustrating the cooling system 120 for the moving body involved in the modified example. Figure 6 The main structural parts shown are different from system 20 in the above embodiments.

[0083] In this mobile cooling system 120, an internal cooling flow rate adjustment device is provided to adjust the flow rate of internal cooling air A2 passing through the evaporator 28. The internal cooling flow rate adjustment device may also be a fan 142b and a motor 142a installed in the internal airflow path B2. The motor 142a rotates the fan 142b, thereby adjusting the flow rate through the evaporator 28. The fan 142b may be installed upstream or downstream of the evaporator 28. The internal cooling flow rate adjustment device may also be a flow rate adjustment valve 140, the same as the flow rate adjustment valve 30 described above.

[0084] Additionally, a third pressure sensor 130 and a refrigerant temperature sensor 132 located downstream of the evaporator 28 are provided. The third pressure sensor 130 is a pressure sensor that detects the pressure of the refrigerant downstream of the evaporator 28. The refrigerant temperature sensor 132 is a temperature sensor that detects the temperature of the refrigerant downstream of the evaporator 28.

[0085] The control unit 150 stores a program 154a in a storage unit 154 corresponding to the storage unit 54 of the control unit 50. In addition to the processing steps described in the program 54a, the program 154a also includes processing steps for performing the fourth processing. Furthermore, the storage unit 154 stores a superheat setpoint 154b and a saturation temperature table 154c. The superheat setpoint 154b is the target superheat at the outlet of the evaporator 28. The saturation temperature table 154c is a table that establishes a correspondence between the saturation temperature and the refrigerant pressure. Based on the detected pressure based on the output of the third pressure sensor 130 and the saturation temperature table 154c, the saturation temperature of the refrigerant relative to the detected pressure is calculated. Based on the difference between this saturation temperature and the detected temperature based on the output of the refrigerant temperature sensor 132 downstream of the evaporator, the superheat is calculated, and the speeds of the motor 142a and fan 142b in the internal cooling flow adjustment device are controlled so that the superheat becomes the superheat setpoint 154b. The superheat setting value 154b can be any value that represents the superheated state, and can be a value set according to inference, experiment, or experience.

[0086] Figure 7 This is a flowchart illustrating an example of the fourth process performed by the control unit 150. The fourth process is performed in parallel with the first to third processes described above.

[0087] In step S31, the saturation temperature at the refrigerant pressure is determined based on the refrigerant pressure and saturation temperature table 154c on the downstream side of the evaporator 28, which is based on the output of the third pressure sensor 130.

[0088] In the next step S32, the superheat H is calculated by subtracting the saturation temperature from the refrigerant temperature on the downstream side of the evaporator 28, which is based on the output of the refrigerant temperature sensor 132 on the downstream side of the evaporator.

[0089] In the next step S33, the superheat target value Ht, defined as the superheat setpoint 154b, is compared with the superheat H. If the superheat H is less than the superheat target value Ht, the process proceeds to step S34, increasing the speed of motor 142a. This increases the heat exchange in evaporator 28, resulting in a higher superheat that approaches the superheat target value Ht. If the superheat H is the same as the superheat target value Ht, the process proceeds to step S35, maintaining the speed of motor 142a. This maintains the state where the superheat H is the same as the superheat target value Ht. If the superheat H is greater than the superheat target value Ht, the process proceeds to step S36, decreasing the speed of motor 142a. This decreases the heat exchange in evaporator 28, resulting in a lower superheat that approaches the superheat target value Ht.

[0090] After steps S34, S35, and S36, proceed to step S37. In step S37, it is determined whether cooling continues, for example, by determining whether a power-on / off command for the system 20 has been issued. If it is determined that cooling has not ended and continues, return to step S31 and repeat the subsequent processing. When it is determined that cooling has ended, this fourth process ends.

[0091] In this system 120, by performing the fourth process described above, the flow rate based on the internal cooling flow adjustment device can be adjusted so that the refrigerant in the downstream side of the evaporator 28 becomes superheated. Therefore, a cooling cycle that effectively utilizes the latent heat region can also be established in the evaporator 28, and cooling can be performed more efficiently.

[0092] When the moving body 12 is an aircraft 12, the external environment changes significantly with its propulsion, thus the cooling performance of the cooling air for the condenser 24, which depends on the external environment of the moving body 12, varies considerably. For example, between the aircraft 12's propulsion in the air and its operation on the ground, the external environment may change from 0.2 atmospheres to 1.0 atmospheres and from -74°C to 60°C, and the system 20 is operated according to this environment. In such cases, by performing the first process described above according to the ambient temperature, and performing the second process in parallel with it, the latent heat region in the condenser 24 can be effectively utilized regardless of changes in the external environment, thus establishing an efficient and stable cooling cycle, which is particularly effective.

[0093] like Figure 8As shown, when the moving body 12 is a water-borne propulsion body 312, it is submerged in water for propulsion. In this case, as the depth changes, the water temperature and pressure fluctuate significantly, thus the temperature of the outer shell of the water-borne propulsion body 312 exposed to the external environment also fluctuates significantly, as does the temperature of the fluid flowing near the outer shell. When the condenser 24 is cooled by a liquid (seawater or water) flowing near the outer shell, changes in the external environment may affect the temperature of the cooling liquid (seawater or water) used to cool the condenser 24. Therefore, by equipping the water-borne propulsion body 312 with the aforementioned systems 20 and 120, and using the liquid (seawater or water) flowing near its outer shell to cool the condenser 24, the latent heat region in the condenser 24 can be effectively utilized regardless of the ambient temperature (especially the temperature affected by depth), thus establishing an efficient and stable cooling cycle.

[0094] Additionally, for example, such as Figure 9 As shown, the moving body 12 can also be a railway vehicle 412. For example, if the railway vehicle 412 is a high-speed railway vehicle 412 that travels at high speeds (e.g., 400 km / h or higher) such as a maglev railway, the total temperature may change due to the speed. Therefore, changes in the external environment caused by the movement may affect the temperature of the air used for cooling the condenser 24 drawn from the outside. Therefore, when the above-mentioned systems 20 and 120 are installed on the railway vehicle 412, the latent heat region in the condenser 24 can be effectively utilized regardless of the speed of the railway vehicle, thus establishing an efficient and stable cooling cycle.

[0095] The mobile body 12 need not be an aircraft 12, a water propulsion vehicle 312, or a railway vehicle 412 as described above. In addition, the mobile body 12 can also be a straddle-type vehicle, a car, etc.

[0096] The functions of the elements disclosed in this specification can be executed using circuits or processing circuits including general-purpose processors, special-purpose processors, integrated circuits, ASICs (Application Specific Integrated Circuits), existing circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. A processor, because it includes transistors and other circuitry, can be considered a processing circuit or circuit. In this disclosure, a circuit, component, or unit is hardware that performs the listed functions, or hardware programmed to perform the listed functions. The hardware can be the hardware disclosed in this specification, or other known hardware programmed or configured to perform the listed functions. Where the hardware is a processor considered a type of circuit, the circuit, unit, or component is a combination of hardware and software, with the software used in the structure of the hardware and / or the processor.

[0097] Furthermore, the structures described in the above embodiments and various modifications can be appropriately combined as long as they do not contradict each other.

[0098] The following methods are disclosed in this specification and accompanying drawings.

[0099] The cooling system for a mobile body according to the first method is a cooling system for a mobile body, comprising: a compressor for compressing a refrigerant; a condenser for condensing the refrigerant compressed by the compressor; an expansion valve for expanding the refrigerant condensed by the condenser; an evaporator for evaporating the refrigerant expanded by the expansion valve to cool fluid within the mobile body; a flow rate adjustment device for adjusting the flow rate of the cooling fluid, which depends on the external environment of the mobile body, as it is guided to the condenser; an ambient temperature sensor for detecting environmental conditions for obtaining the ambient temperature exposed to the condenser through the cooling fluid; and a pressure sensor for detecting the pressure of the condenser. The system includes: a pressure sensor for the refrigerant in the condenser; a temperature sensor for detecting the temperature of the refrigerant downstream of the condenser; and a control unit for performing a first process and a second process. The first process involves adjusting the flow rate of the cooling fluid using a flow adjustment device based on the ambient temperature obtained from the output of a sensor and the output of the pressure sensor, so that the pressure of the refrigerant in the condenser is greater than the saturation pressure of the refrigerant at the ambient temperature. The second process involves adjusting the opening of the expansion valve based on the output of the pressure sensor and the output of the temperature sensor, so that the refrigerant downstream of the condenser is in a subcooled state.

[0100] According to the cooling system for mobile bodies involved in the first method, a first process and a second process are performed. The first process involves adjusting the flow rate of the cooling fluid using a flow adjustment device so that the pressure of the refrigerant in the condenser is greater than the saturation pressure of the refrigerant at ambient temperature. The second process involves adjusting the opening of the expansion valve so that the refrigerant in the downstream side of the condenser is in a subcooled state. Therefore, the latent heat region in the condenser can be effectively utilized, enabling a highly efficient and stable cooling cycle.

[0101] The second approach is the cooling system for the mobile body involved in the first approach. The pressure sensor includes a first pressure sensor located upstream of the condenser and a second pressure sensor located downstream of the condenser. The output of the first pressure sensor is used in the first process, and the output of the second pressure sensor is used in the second process. In this case, the aforementioned cooling processes can be performed taking into account pressure losses in the condenser.

[0102] The third method is a cooling system for a mobile body as described in the first or second method. The second process is as follows: based on the output of the pressure sensor, the saturation temperature relative to the refrigerant pressure in the condenser is calculated; this saturation temperature is compared with the temperature of the refrigerant downstream of the condenser based on the output of the temperature sensor; and based on the comparison result, the opening of the expansion valve is adjusted to make the refrigerant in the downstream side of the condenser subcooled. In this case, the saturation temperature relative to the refrigerant pressure in the condenser and the temperature of the refrigerant downstream of the condenser can be compared, and the opening of the expansion valve can be adjusted based on the comparison result to make the refrigerant in the downstream side of the condenser subcooled.

[0103] The fourth method is a cooling system for mobile bodies involved in any of the first to third methods, further comprising a cooling temperature detection sensor for detecting the cooling temperature of the evaporator, and the control unit performs a third process of controlling the compressor based on the output of the cooling temperature detection sensor and the target cooling temperature. Thus, by controlling the compressor, the cooling capacity of the cooling system for mobile bodies can be controlled.

[0104] The fifth method is a cooling system for a mobile body involved in any of the first to fourth methods. The control unit calculates the total temperature of the mobile body based on the output of a sensor obtained from the ambient temperature, and uses the calculated total temperature as the ambient temperature to perform the first process. Thus, the first process can be performed based on a suitable total temperature, which is the temperature exposed to the condenser.

[0105] The sixth method is a cooling system for a mobile body according to any one of the first to fifth methods, wherein the flow adjustment device includes at least one of a flow adjustment valve for adjusting the flow rate of the cooling fluid and a fan for conveying the cooling fluid. Thus, the flow rate can be adjusted by at least one of the flow adjustment valve and the fan.

[0106] The seventh method is a cooling system for a mobile body as described in any of the first to sixth methods, wherein the control unit is configured as a physical computer that performs the first and second processes. Thus, the first and second processes can be performed by a single computer.

[0107] The eighth method is a cooling system for a mobile body according to any one of the first to seventh methods, comprising: a third pressure sensor for detecting the pressure of the refrigerant downstream of the evaporator; a refrigerant temperature sensor downstream of the evaporator for detecting the temperature of the refrigerant downstream of the evaporator; and an internal cooling flow adjustment device for adjusting the flow rate of fluid within the mobile body as it is guided to the evaporator. The control unit adjusts the flow rate of the fluid within the mobile body via the internal cooling flow adjustment device based on the output of the third pressure sensor and the output of the refrigerant temperature sensor downstream of the evaporator, thereby making the refrigerant in a superheated state downstream of the evaporator. Thus, the latent heat region can also be effectively utilized in the evaporator.

[0108] The ninth method is a cooling system for a moving body, as described in any of the first to eighth methods, where the moving body is an aircraft, a water-powered vehicle, or a railway vehicle. In this case, when the aircraft, water-powered vehicle, or railway vehicle is propelled, the cooling performance of the cooling fluid, which depends on the external environment of the moving body, varies considerably due to significant changes in the external environment. Therefore, by performing the first and second processes, the latent heat region in the condenser can be effectively utilized regardless of changes in the external environment, thus establishing an efficient and stable cooling cycle.

[0109] The tenth embodiment involves a mobile body with a cooling system, comprising a mobile body cooling system as described in any one of the first to eighth embodiments, and a mobile body capable of moving while having the mobile body cooling system assembled thereon. Thus, an efficient and stable cooling cycle can be established within the mobile body.

[0110] The eleventh method involves a mobile body with a cooling system, as described in the tenth method. This mobile body is an aircraft, a water-propelled vehicle, or a railway vehicle. In this case, as the mobile body moves in the atmosphere, water, or on land, the external environment changes significantly, and the cooling performance of the cooling fluid for the condenser, which depends on the external environment of the mobile body, varies considerably. Therefore, by performing the first and second processes, the latent heat region in the condenser can be effectively utilized regardless of changes in the external environment, thus establishing an efficient and stable cooling cycle.

[0111] The cooling control method involved in the twelfth method is a cooling control method for controlling a cooling system in which refrigerant circulates in a compressor, condenser, expansion valve, and evaporator by a moving body. The cooling control method performs: a first process, adjusting the flow rate of the cooling fluid guided to the condenser according to the ambient temperature exposed to the condenser and the pressure of the refrigerant in the condenser so that the pressure of the refrigerant in the condenser is greater than the saturation pressure of the refrigerant at the ambient temperature; and a second process, adjusting the opening of the expansion valve according to the pressure of the refrigerant in the condenser and the temperature of the refrigerant downstream of the condenser so that the refrigerant downstream of the condenser is in a subcooled state.

[0112] According to this cooling control method, a first process and a second process are performed. The first process adjusts the flow rate of the cooling fluid guided to the condenser so that the pressure of the refrigerant in the condenser is greater than the saturation pressure of the refrigerant at ambient temperature. The second process adjusts the opening of the expansion valve so that the refrigerant on the downstream side of the condenser is in a subcooled state. Therefore, the latent heat region in the condenser can be effectively utilized, enabling an efficient and stable cooling cycle.

[0113] The thirteenth method is the cooling control method involved in the twelfth method. The first process is based on the refrigerant pressure detected upstream of the condenser, and the second process is based on the refrigerant pressure detected downstream of the condenser. Therefore, the control involved in cooling can take into account the pressure loss in the condenser.

[0114] The fourteenth method is the cooling control method involved in the twelfth or thirteenth method. The second process is as follows: The saturation temperature relative to the refrigerant pressure in the condenser is determined; this saturation temperature is compared with the temperature of the refrigerant downstream of the condenser; and based on the comparison result, the opening of the expansion valve is adjusted to make the refrigerant in the downstream side of the condenser subcooled. In this case, the saturation temperature relative to the refrigerant pressure in the condenser can be compared with the temperature of the refrigerant downstream of the condenser, and the opening of the expansion valve can be adjusted based on the comparison result to make the refrigerant in the downstream side of the condenser subcooled.

[0115] The fifteenth method is a cooling control method involved in any of the twelve to fourteenth methods, wherein the cooling control method performs a third process of controlling the compressor based on the cooling temperature of the evaporator and a target cooling temperature. Thus, the cooling capacity of the cooling system can be controlled by controlling the compressor.

[0116] The sixteenth method is a cooling control method involved in any of the twelfth to fifteenth methods, wherein the cooling control method calculates the total temperature of the moving body and uses the calculated total temperature as the ambient temperature to perform the first process. Thus, the first process can be performed based on an appropriate total temperature, which is the temperature exposed to the condenser.

[0117] The seventeenth method is a cooling control method involved in any of the twelve to sixteenth methods, wherein the moving body is an aircraft, a water-powered propulsion vehicle, or a railway vehicle. When an aircraft, water-powered propulsion vehicle, or railway vehicle is propelled, the cooling performance of the cooling fluid for the condenser, which depends on the external environment of the moving body, varies considerably due to significant changes in the external environment. Therefore, under such circumstances, by performing the first and second processes, the latent heat region in the condenser can be effectively utilized regardless of changes in the external environment, thus establishing an efficient and stable cooling cycle.

[0118] The foregoing description is illustrative in all respects and the invention is not limited thereto. Numerous variations not illustrated are to be understood without departing from the scope of the invention.

[0119] Symbol Explanation

[0120] 10: Mobile units with cooling systems

[0121] 12: Mobile vehicle (aircraft)

[0122] 20, 120: Cooling system for mobile units

[0123] 22: Compressor

[0124] 24: Condenser

[0125] 26: Expansion valve

[0126] 28: Evaporator

[0127] 30: Flow regulating valve

[0128] 31a: Motor

[0129] 31b: Fan

[0130] 34a: Motor

[0131] 34b: Fan

[0132] 40: First pressure sensor

[0133] 41: Second pressure sensor

[0134] 42: Temperature sensor

[0135] 43: Cooling temperature detection sensor

[0136] 45: Sensor for obtaining ambient temperature

[0137] 46: Sensor for obtaining ambient temperature

[0138] 50, 150: Control Department

[0139] 52: Processor

[0140] 54, 154: Storage Department

[0141] 54a, 154a: Program

[0142] 54b: Target cooling temperature

[0143] 54c: Pressure deviation value

[0144] 54d: Subcooling setpoint

[0145] 58: Input Section

[0146] 130: Third pressure sensor

[0147] 132: Refrigerant temperature sensor downstream of evaporator

[0148] 140: Flow regulating valve

[0149] 142a: Motor

[0150] 142b: Fan

[0151] 154b: Superheat setpoint

[0152] 312: Underwater Propulsion

[0153] 412: Railway vehicles.

Claims

1. A cooling system for a mobile body, which is a mobility system for a mobile body, the mobile body cooling system comprising: The compressor compresses the refrigerant; A condenser that condenses the refrigerant compressed by the compressor; An expansion valve allows the refrigerant condensed by the condenser to expand. An evaporator cools the fluid within the moving body by evaporating the refrigerant that has expanded by the expansion valve. A flow adjustment device adjusts the flow rate of cooling fluid, which depends on the external environment of the moving body, as it is guided to the condenser; An ambient temperature sensor is used to detect the environmental conditions used to obtain the ambient temperature of the condenser exposed to the cooling fluid. A pressure sensor detects the pressure of the refrigerant in the condenser; A temperature sensor detects the temperature of the refrigerant on the downstream side of the condenser; as well as The control unit executes a first process and a second process. The first process involves adjusting the flow rate of the cooling fluid using the flow adjustment device based on the ambient temperature output from the sensor and the output from the pressure sensor, so that the pressure of the refrigerant in the condenser is greater than the saturation pressure of the refrigerant at the ambient temperature. The second process involves adjusting the opening of the expansion valve based on the outputs of the pressure sensor and the temperature sensor, so that the refrigerant on the downstream side of the condenser is in a subcooled state. The control unit calculates the total temperature of the moving body based on the output of the sensor obtained from the ambient temperature, and uses the calculated total temperature as the ambient temperature to perform the first process.

2. The cooling system for a mobile body according to claim 1, wherein, The pressure sensor includes a first pressure sensor disposed on the upstream side of the condenser and a second pressure sensor disposed on the downstream side of the condenser. The output of the first pressure sensor is used in the first process, and the output of the second pressure sensor is used in the second process.

3. The cooling system for a mobile body according to claim 1 or 2, wherein, The second process is as follows: based on the output of the pressure sensor, the saturation temperature relative to the refrigerant pressure in the condenser is calculated, and the saturation temperature is compared with the temperature of the refrigerant on the downstream side of the condenser based on the output of the temperature sensor. Based on the comparison result, the opening of the expansion valve is adjusted so that the refrigerant on the downstream side of the condenser is in a subcooled state.

4. The cooling system for a mobile body according to claim 1 or 2, wherein, The cooling system for the mobile body also includes a cooling temperature detection sensor for detecting the cooling temperature of the evaporator. The control unit performs a third process of controlling the compressor based on the output of the cooling temperature detection sensor and the target cooling temperature.

5. The cooling system for a mobile body according to claim 1 or 2, wherein, The flow adjustment device includes at least one of a flow adjustment valve for adjusting the flow rate of cooling fluid and a fan for conveying cooling fluid.

6. The cooling system for a mobile body according to claim 1 or 2, wherein, The control unit is configured as a physical computer that performs the first process and the second process.

7. The cooling system for a mobile body according to claim 1 or 2, wherein, The cooling system for the mobile body includes: The third pressure sensor detects the pressure of the refrigerant on the downstream side of the evaporator; A refrigerant temperature sensor downstream of the evaporator detects the temperature of the refrigerant downstream of the evaporator; and An internal cooling flow adjustment device adjusts the flow rate of fluid within the moving body as it is guided to the evaporator. The control unit adjusts the flow rate of the fluid in the moving body through the internal cooling flow adjustment device based on the output of the third pressure sensor and the output of the refrigerant temperature sensor downstream of the evaporator, so that the refrigerant downstream of the evaporator becomes superheated.

8. The cooling system for a mobile body according to claim 1 or 2, wherein, The moving body is an aircraft, a water-powered vehicle, or a railway vehicle.

9. A mobile body with a cooling system, comprising: Cooling system for a mobile body according to any one of claims 1 to 7; and A mobile body capable of moving while equipped with the cooling system for the mobile body.

10. The mobile body with a cooling system according to claim 9, wherein, The moving body is an aircraft, a water-powered vehicle, or a railway vehicle.

11. A cooling control method for controlling a cooling system in a moving body in which refrigerant circulates in a compressor, condenser, expansion valve, and evaporator, wherein, The cooling control method performs a first process and a second process. The first process involves adjusting the flow rate of the cooling fluid directed to the condenser based on the ambient temperature exposed to the condenser and the pressure of the refrigerant in the condenser, so that the pressure of the refrigerant in the condenser is greater than the saturation pressure of the refrigerant at the ambient temperature. The second process involves adjusting the opening of the expansion valve based on the refrigerant pressure in the condenser and the refrigerant temperature downstream of the condenser, so that the refrigerant downstream of the condenser is in a subcooled state. In the cooling control method, the total temperature of the moving body is calculated, and the calculated total temperature is used as the ambient temperature to perform the first process.

12. The cooling control method according to claim 11, wherein, The first process is based on the refrigerant pressure detected on the upstream side of the condenser, and the second process is based on the refrigerant pressure detected on the downstream side of the condenser.

13. The cooling control method according to claim 11 or 12, wherein, The second process is as follows: the saturation temperature relative to the refrigerant pressure in the condenser is determined, and this saturation temperature is compared with the temperature of the refrigerant on the downstream side of the condenser. Based on the comparison result, the opening of the expansion valve is adjusted so that the refrigerant is in a subcooled state on the downstream side of the condenser.

14. The cooling control method according to claim 11 or 12, wherein, In the cooling control method, a third process is performed to control the compressor based on the cooling temperature of the evaporator and the target cooling temperature.

15. The cooling control method according to claim 11 or 12, wherein, The moving body is an aircraft, a water-powered vehicle, or a railway vehicle.

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