Temperature control method for marine propulsion systems and batteries

Abstract

This ship propulsion device comprises a motor, a battery, a temperature adjustment water flow channel including a first path through a first heat exchange part capable of heat exchange with the battery, a path switching unit capable of switching between a state of allowing and a state of restricting flow of water to the first path, a first temperature sensor for detecting the battery temperature, a second temperature sensor for detecting a water temperature, and a control unit for controlling the path switching unit. The control unit places the path switching unit in the allowing state when the battery temperature is higher than an upper-limit value and the water temperature is less than the battery temperature, and / or when the battery temperature is less than a lower-limit temperature and the water temperature exceeds the battery temperature, and places the path switching unit in the restricting state when the battery temperature is higher than the upper-limit value and the water temperature exceeds the battery temperature, and / or when the battery temperature is less than the lower-limit value and the water temperature is less than the battery temperature.

Description

Technical Field

[0001] The present disclosure relates to a temperature adjustment method for a marine propulsion device and a battery.

Background Art

[0002] Marine propulsion devices such as outboard motors generally employ internal combustion engines such as gasoline engines as power sources. In recent years, however, marine propulsion devices that employ electric motors as power sources have attracted attention from the perspective of reducing environmental impact. Regarding electric marine propulsion devices, for example, Patent Document 1 discloses a technique for cooling a battery by taking in water from the outside.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] As a result of intensive studies, the present inventor has found that there is room for improving the performance of a conventional electric marine propulsion device from the perspective of temperature adjustment of the battery.

[0005] The present disclosure has been made in view of such circumstances, and one of its objects is to provide a technique for improving the performance of an electric marine propulsion device.

[0006] One aspect of the present disclosure is a ship propulsion system. The system includes a motor for driving a propulsion unit, a battery for supplying power to the motor, a temperature-controlled water channel through which water from outside the hull flows, including a first path that passes through a first heat exchange unit connected to the battery in a heat-exchangeable manner, a path switching unit that can switch between an allowable state that permits the flow of water to the first path and a restrictive state that restricts the flow, a first temperature sensor for detecting the temperature of the battery, a second temperature sensor for detecting the temperature of the water, and a control unit that controls the path switching unit based on the battery temperature detected by the first temperature sensor and the water temperature detected by the second temperature sensor. The control unit controls the path switching unit to take the allowable state when the battery temperature exceeds a predetermined upper limit and the water temperature is less than the battery temperature, and when the battery temperature is less than a predetermined lower limit and the water temperature exceeds the battery temperature, and controls the path switching unit to take the restrictive state when the battery temperature exceeds the upper limit and the water temperature exceeds the battery temperature, and when the battery temperature is less than the lower limit and the water temperature is less than the battery temperature.

[0007] Another aspect of the present disclosure is a method for temperature control of a battery mounted in a ship's propulsion system. The method includes performing heat exchange between water and the battery when the battery temperature exceeds a predetermined upper limit and the water temperature outside the hull is below the battery temperature, and at least one of the following: when the battery temperature exceeds the upper limit and the water temperature is below the battery temperature, and at least one of the following: when the battery temperature exceeds the upper limit and the water temperature is above the battery temperature, and when the battery temperature is below the lower limit and the water temperature is below the battery temperature.

[0008] Any combination of the above components, as well as any conversion of the expressions of this disclosure between methods, apparatus, systems, etc., are also valid forms of this disclosure.

[0009] According to this disclosure, the performance of electric propulsion systems for ships can be improved. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram of a ship's propulsion system. [Figure 2] This is a schematic diagram showing the first pathway for temperature-controlled water. [Figure 3] This is a schematic diagram showing the second pathway for temperature-controlled water. [Figure 4] This is a schematic diagram showing the flow path structure of temperature-controlled water in a modified ship's propulsion system. [Modes for carrying out the invention]

[0011] The present disclosure will be described below with reference to the drawings, based on preferred embodiments. The embodiments are illustrative and not limiting, and not all features or combinations thereof described in the embodiments are necessarily essential to the present disclosure. The same or equivalent components, members, and processes shown in each drawing are denoted by the same reference numerals, and redundant descriptions are omitted where appropriate. The scale and shape of each part shown in each drawing are set for convenience to facilitate explanation and are not to be interpreted restrictively unless otherwise specified. Furthermore, where terms such as "first," "second," etc. are used in this specification or claims, unless otherwise specified, these terms do not indicate any order or importance, but are used to distinguish one configuration from another. In addition, some components that are not important for explaining the embodiments are omitted in each drawing.

[0012] Figure 1 is a schematic diagram of a ship propulsion system 1. In this embodiment, the ship propulsion system 1 is an outboard motor as an example. However, the ship propulsion system 1 may also be an inboard motor or an inboard / outboard motor. The ship propulsion system 1 comprises an upper housing 2, an intermediate housing 4, and a lower housing 6. The upper housing 2 is substantially rectangular and is positioned higher than the water surface WS. The lower housing 6 is positioned lower than the water surface WS. The intermediate housing 4 is a cylindrical shape extending vertically and connects the upper housing 2 and the lower housing 6. A bracket device 8 is provided on the intermediate housing 4. The ship propulsion system 1 is supported by the hull 100 via the bracket device 8. In this embodiment, the ship propulsion system 1 is attached to the transom 102 of the hull 100.

[0013] The marine propulsion system 1 can rotate horizontally and vertically. The upper housing 2 is provided with a steering handle 10 that extends toward the hull 100. The ship's crew can steer the hull 100 by changing the direction of the marine propulsion system 1 by swinging the steering handle 10 horizontally. A throttle grip for adjusting the output of the motor 16 is provided at the tip of the steering handle 10. The steering handle 10 is also provided with a shift switch for switching between forward and reverse rotation of the motor 16.

[0014] The marine propulsion system 1 also includes a battery 12, a power converter 14, a motor 16, and a thruster 18. The battery 12 is housed in the upper housing 2. Preferably, the battery 12 is detachably housed in the upper housing 2. The battery 12 has a plurality of batteries 22 and a battery pack 24. The plurality of batteries 22 are housed in the battery pack 24 in a series and / or parallel configuration. The battery pack 24 is a metal or resin container. The battery pack 24 is preferably waterproof. Note that there may be only one battery 22.

[0015] As an example, battery 22 is a rechargeable secondary battery such as a lithium-ion battery, nickel-metal hydride battery, or nickel-cadmium battery. Battery 22 has a known structure. As an example, battery 22 has a structure in which an electrode group is housed together with a non-aqueous electrolyte in an outer casing. A safety valve is provided in the outer casing. The safety valve opens when the internal pressure of the outer casing rises above a predetermined value. This allows the gas inside battery 22 to be released.

[0016] The battery 12 supplies power to the motor 16 via the power converter 14. For example, the power converter 14 is housed in the intermediate housing 4 or the lower housing 6, and the motor 16 is housed in the lower housing 6. The power converter 14 and the motor 16 may be integrated. The power converter 14 may also be omitted. The power converter 14 converts the power from the battery 12 and supplies it to the motor 16. For example, the power converter 14 is an inverter and controls the voltage and frequency of the battery 12 to change the output of the motor 16. The motor 16 can be any motor that can convert the power supplied from the battery 12 into motor power, and its structure is not particularly limited.

[0017] A thruster 18 is connected to the motor 16. By receiving power from the battery 12, the motor 16 is driven, which in turn drives the thruster 18. In this embodiment, the thruster 18 is a propeller and is connected to the output shaft of the motor 16 via a propeller shaft 26. The thruster 18 may be a known thruster other than a propeller, such as a water jet thruster. The power converter 14 and the motor 16 may also be housed in the upper housing 2. In this case, the output shaft of the motor 16 and the propeller shaft 26 are connected to each other via a drive shaft housed in the intermediate housing 4.

[0018] Furthermore, the ship's propulsion system 1 includes a temperature-controlled water channel 30, a pump 32, a heat exchange member 34, a path switching unit 38, a first temperature sensor 40, a second temperature sensor 42, and a control unit 44. The temperature-controlled water channel 30 is a pipeline through which temperature-controlled water, which is water used to adjust the temperature of the battery 12, flows. In this embodiment, the temperature-controlled water is water outside the hull 100. In other words, the water in which the hull 100 is floating (seawater, lake water, river water, etc.) is used as temperature-controlled water.

[0019] The temperature-controlled water flow path 30 extends from inside the upper housing 2 to inside the lower housing 6. The temperature-controlled water flow path 30 has a first flow path section 30a, a second flow path section 30b, a third flow path section 30c, and a fourth flow path section 30d. The first flow path section 30a extends from inside the lower housing 6 to inside the upper housing 2. One end of the first flow path section 30a is located inside the lower housing 6 and communicates with the water, forming the temperature-controlled water intake 30e. The first flow path section 30a extends upward inside the intermediate housing 4 to the upper housing 2. A pump 32 is provided in the middle of the first flow path section 30a. A known pump can be used as the pump 32. The pump 32 is driven by power supplied from the battery 12 and pumps up temperature-controlled water from one end of the first flow path section 30a. The pump 32 may also be provided in the third flow path section 30c. The pump 32 may also be driven by the rotation of the motor 16 or the rotation of the drive shaft.

[0020] The second flow channel section 30b is located inside the upper housing 2. The other end of the first flow channel section 30a is connected to one end of the second flow channel section 30b. The second flow channel section 30b is connected to the heat exchange member 34 in a heat exchange manner. The heat exchange member 34 is connected to the battery 12 in a heat exchange manner. Therefore, the second flow channel section 30b is capable of exchanging heat with the battery 12 via the heat exchange member 34. At least a portion of the second flow channel section 30b constitutes the first heat exchange section 46, which is connected to the battery 12 in a heat exchange manner.

[0021] As the heat exchange member 34, a known one can be adopted. For example, the heat exchange member 34 is composed of a plate material with high thermal conductivity such as a metal plate. And the second flow path portion 30b is fixed to one main surface of the heat exchange member 34 by a thermally conductive adhesive or the like. Note that the second flow path portion 30b and the heat exchange member 34 may be fixed by screwing in a state where they are in direct contact or a heat transfer material is interposed, or may be fixed by joining such as welding or brazing. Also, the battery 12 is placed on the other main surface of the heat exchange member 34, and the bottom surface of the battery pack 24 contacts the heat exchange member 34. The method of connecting the second flow path portion 30b and the battery 12 so as to enable heat exchange is not limited to the above. For example, the heat exchange member 34 may be omitted.

[0022] The third flow path portion 30c extends from the inside of the upper housing 2 to the inside of the lower housing 6. One end side of the third flow path portion 30c is disposed inside the upper housing 2 and connected to the other end side of the second flow path portion 30b. The third flow path portion 30c extends downward inside the intermediate housing 4 and reaches the inside of the lower housing 6. The other end side of the third flow path portion 30c is disposed inside the lower housing 6 and communicates with water, constituting a discharge port 30f for temperature-controlled water.

[0023] In the present embodiment, the power converter 14 is connected to the third flow path portion 30c so as to enable heat exchange. Therefore, at least a part of the third flow path portion 30c constitutes a second heat exchange portion 48 that is connected to the power converter 14 so as to enable heat exchange. Also, in the present embodiment, the motor 16 is also connected to the second heat exchange portion 48 so as to enable heat exchange. Each of the power converter 14 and the motor 16 and the third flow path portion 30c can be connected so as to enable heat exchange in the same manner as the connection method between the second flow path portion 30b and the heat exchange member 34. Note that the thermal connection of the power converter 14 and the motor 16 to the second heat exchange portion 48 is optional.

[0024] The external water as temperature-controlled water, which is pumped up from one end side of the first flow path portion 30a by the pump 32, passes through the first flow path portion 30a, the second flow path portion 30b, and the third flow path portion 30c, and is discharged from the other end side of the third flow path portion 30c. The temperature-controlled water exchanges heat with the battery 12 in the process of passing through the first heat exchange portion 46. Thereby, the battery 12 is cooled or heated. Also, the temperature-controlled water takes heat from the power converter 14 and the motor 16 in the process of passing through the second heat exchange portion 48. Thereby, the power converter 14 and the motor 16 are cooled.

[0025] A pilot water discharge port 50 is provided in the middle of the third flow path portion 30c. The pilot water discharge port 50 is disposed above the water surface WS. Also, in the present embodiment, the pilot water discharge port 50 is disposed above the second heat exchange portion 48 (on the upstream side of the flow of the temperature-controlled water). A part of the water that has cooled or heated the battery 12 in the first heat exchange portion 46 is discharged from the pilot water discharge port 50 to the water surface WS. Thereby, the crew of the ship can visually confirm that the temperature control mechanism is operating normally.

[0026] The fourth flow path portion 30d is disposed, for example, in the intermediate portion housing 4. One end side of the fourth flow path portion 30d is connected to the middle of the first flow path portion 30a. The other end side of the fourth flow path portion 30d is connected to the middle of the third flow path portion 30c. The connection position between the other end side of the fourth flow path portion 30d and the third flow path portion 30c is, for example, above the pilot water discharge port 50. By flowing the temperature-controlled water from the first flow path portion 30a through the fourth flow path portion 30d to the third flow path portion 30c, the temperature-controlled water can be guided to the discharge port 30f without passing through the first heat exchange portion 46. Note that the temperature-controlled water flowing through the fourth flow path portion 30d also passes through the second heat exchange portion 48. Therefore, whether the temperature-controlled water flows through the second flow path portion 30b or through the fourth flow path portion 30d, the power converter 14 and the motor 16 can be cooled.

[0027] One end of the fourth flow path section 30d is connected to the first flow path section 30a via a path switching unit 38. The path switching unit 38 can switch whether the temperature-controlled water flowing from the intake 30e is sent to the second flow path section 30b side or to the fourth flow path section 30d side. The path switching unit 38 can be configured as a known flow path switching solenoid valve or the like, and its state is switched according to a control signal output from the control unit 44.

[0028] The first temperature sensor 40 detects the temperature of the battery 12. The first temperature sensor 40 can be made up of a known temperature sensor such as a thermistor. The battery temperature measurement position, that is, the mounting position of the first temperature sensor 40 relative to the battery 12, can be set appropriately based on experiments and simulations by the designer. The first temperature sensor 40 sends the detection result to the control unit 44.

[0029] The second temperature sensor 42 detects the temperature of the external water. The second temperature sensor 42 can be made up of a known temperature sensor such as a thermistor. The water temperature measurement location can be set as appropriate based on experiments or simulations conducted by the designer. The second temperature sensor 42 sends the detection result to the control unit 44.

[0030] The control unit 44 controls the path switching unit 38 based on the battery temperature detected by the first temperature sensor 40 and the water temperature detected by the second temperature sensor 42. The control unit 44 is implemented as a hardware configuration using elements and circuits such as a computer's CPU and memory, and as a software configuration using a computer program, etc., but in Figure 1 it is depicted as a functional block realized by the cooperation of these. It will be obvious to those skilled in the art that this functional block can be realized in various ways by combinations of hardware and software.

[0031] Next, the temperature control of the battery 12 performed by the control unit 44, in other words, the switching control of the temperature-controlled water path, will be described. Figure 2 is a schematic diagram showing the first temperature-controlled water path R1. Figure 3 is a schematic diagram showing the second temperature-controlled water path R2. The temperature-controlled water flow path 30 includes the first path R1 and the second path R2. The first path R1 is a path that passes through the first heat exchange unit 46, as shown in Figure 2. In addition, the first path R1 in this embodiment passes through the second heat exchange unit 48 in addition to the first heat exchange unit 46. The second path R2 is a path that passes through the second heat exchange unit 48, without passing through the first heat exchange unit 46, as shown in Figure 3.

[0032] The first path R1 consists of the portion of the first flow path section 30a downstream of the path switching section 38 (towards the second flow path section 30b), the second flow path section 30b, and the third flow path section 30c. In the first path R1, the temperature-controlled water passes through the first heat exchange section 46, the pilot water outlet 50, and the second heat exchange section 48 before being discharged from the outlet 30f. As a result, the temperature-controlled water exchanges heat with the battery 12, the power converter 14, and the motor 16.

[0033] The second path R2 consists of the fourth flow channel section 30d and the portion downstream (discharge port 30f side) of the connection point between the third flow channel section 30c and the fourth flow channel section 30d. In the second path R2, the temperature-controlled water is discharged from the discharge port 30f through the pilot water discharge port 50 and the second heat exchange section 48. Therefore, the temperature-controlled water does not exchange heat with the battery 12, but exchanges heat with the power converter 14 and the motor 16.

[0034] The path switching unit 38 can switch between an allowable state, which permits the flow of water to the first path R1, and a restrictive state, which restricts the flow. As described above, the path switching unit 38 in this embodiment connects the first flow channel 30a and the fourth flow channel 30d, and if the temperature-controlled water is not sent to the second flow channel 30b side, it is sent to the fourth flow channel 30d side. Therefore, the path switching unit 38 in this embodiment switches the path of the temperature-controlled water between the first path R1 and the second path R2. For this reason, when the path switching unit 38 is in the allowable state, the flow of water to the second path R2 is restricted, and when it is in the restrictive state, the flow of water to the second path R2 is permitted. Note that the installation location of the path switching unit 38 is not limited as long as it can switch between the allowable state and the restrictive state. For example, the path switching unit 38 may be provided in the third flow channel 30c.

[0035] "Restricting the flow of water" means reducing the water flow rate compared to when water flow is permitted. Therefore, when the route switching unit 38 is in the restricted state, a smaller amount of water may flow into the first route R1 than when it is in the permitted state. However, it is preferable that the water flow rate into the first route R1 is zero when it is in the restricted state.

[0036] The control unit 44 switches between the first path R1 and the second path R2 based on the relative magnitudes of the battery temperature detected by the first temperature sensor 40 and the water temperature detected by the second temperature sensor 42. Specifically, the control unit 44 stores predetermined upper and lower limits for the battery temperature. The upper and lower limits for the battery temperature can be appropriately set based on experiments and simulations by the designer, depending on the temperature range suitable for maintaining the performance and extending the lifespan of the battery 12. For example, the upper limit is 30°C and the lower limit is 25°C.

[0037] The control unit 44 controls the route switching unit 38 to enter an acceptable state in at least one of the following cases: when the battery temperature exceeds a predetermined upper limit and the water temperature is below the battery temperature, and when the battery temperature is below a predetermined lower limit and the water temperature exceeds the battery temperature. Preferably, the control unit 44 sets the route switching unit 38 to an acceptable state in both cases: when the battery temperature exceeds the upper limit and the water temperature is below the battery temperature, and when the battery temperature is below the lower limit and the water temperature exceeds the battery temperature.

[0038] This allows for effective cooling of the battery 12 when its temperature exceeds the appropriate range using temperature-controlled water. Furthermore, it allows for effective heating of the battery 12 when its temperature falls below the appropriate range using temperature-controlled water. Heating the battery 12 reduces the internal resistance of the battery 22, improving its input / output characteristics and thus improving energy efficiency. Additionally, it reduces the opportunities for regeneration and charging of the battery 12 when it is at a low temperature, thereby suppressing battery degradation.

[0039] Furthermore, the control unit 44 controls the route switching unit 38 to enter a restricted state in at least one of the following cases: when the battery temperature exceeds the upper limit and the water temperature exceeds the battery temperature, and when the battery temperature is below the lower limit and the water temperature is below the battery temperature. Preferably, the control unit 44 puts the route switching unit 38 into a restricted state in both cases: when the battery temperature exceeds the upper limit and the water temperature exceeds the battery temperature, and when the battery temperature is below the lower limit and the water temperature is below the battery temperature.

[0040] This prevents situations where attempting to cool a battery 12 that is above the appropriate temperature range with temperature-controlled water would actually increase the battery temperature, or where a battery 12 that is below the appropriate temperature range would be further cooled by the temperature-controlled water. If the battery temperature exceeds the upper limit and the water temperature exceeds the battery temperature, the battery 12 is cooled by air cooling or the like. Also, if the battery temperature is below the lower limit and the water temperature is below the battery temperature, the battery 12 is heated by self-heating due to discharge, etc.

[0041] When the battery temperature exceeds the upper limit and the water temperature is equal to the battery temperature, and when the battery temperature is below the lower limit and the water temperature is equal to the battery temperature, the path switching unit 38 may be set to either an allowable state or a restrictive state. Also, when the battery temperature is above the lower limit and below the upper limit, that is, when the battery temperature is within the appropriate temperature range, the control unit 44 may, for example, set the path switching unit 38 to a restrictive state. This restricts the temperature adjustment of the battery 12 by the temperature-controlled water. Note that the path switching unit 38 may be set to an allowable state when the battery temperature is within the appropriate temperature range.

[0042] Regardless of whether the path switching unit 38 is in the permissible or restricted state, in other words, regardless of whether the first path R1 or the second path R2 is selected, the temperature-controlled water passes through the second heat exchange unit 48. Therefore, the power converter 14 and motor 16 always exchange heat with the temperature-controlled water. Generally, the power converter 14 and motor 16, while in operation, are always at a higher temperature than the temperature that external water can reach. Furthermore, there is virtually no possibility that the temperature of the power converter 14 and motor 16 will deviate from the appropriate temperature range due to heat exchange with water. Therefore, it is not a problem to always flow water through the second heat exchange unit 48 regardless of the water temperature.

[0043] As described above, the ship propulsion system 1 according to this embodiment includes a motor 16 that drives a propulsion machine 18, a battery 12 that supplies power to the motor 16, a temperature-controlled water flow path 30 through which water from outside the hull 100 flows, including a first path R1 that passes through a first heat exchange unit 46 connected to the battery 12 in a heat-exchangeable manner, a path switching unit 38 that can switch between an allowable state that permits the flow of water to the first path R1 and a restrictive state that restricts the flow, a first temperature sensor 40 that detects the temperature of the battery 12, a second temperature sensor 42 that detects the temperature of the water outside, and a control unit 44 that controls the path switching unit 38 based on the battery temperature detected by the first temperature sensor 40 and the water temperature detected by the second temperature sensor 42.

[0044] The control unit 44 controls the route switching unit 38 to enter an acceptable state in at least one of the following cases: when the battery temperature exceeds a predetermined upper limit and the water temperature is below the battery temperature, and when the battery temperature is below a predetermined lower limit and the water temperature exceeds the battery temperature. The control unit 44 also controls the route switching unit 38 to enter a restricted state in at least one of the following cases: when the battery temperature exceeds the upper limit and the water temperature exceeds the battery temperature, and when the battery temperature is below the lower limit and the water temperature is below the battery temperature.

[0045] Conventional marine propulsion systems typically use internal combustion engines such as gasoline engines, which are always hotter than the ambient water temperature while in operation. Furthermore, there is virtually no possibility of the internal combustion engine temperature falling outside the appropriate temperature range due to heat exchange with water. For this reason, conventional marine propulsion systems have always cooled the internal combustion engine with ambient water while in operation. In contrast, the temperature of the battery 12 installed in the electric marine propulsion system 1 may fall outside the appropriate temperature range due to heat exchange with ambient water, depending on the water temperature.

[0046] In contrast, the marine propulsion system 1 of this embodiment performs heat exchange between water and the battery 12 in at least one of the following cases: when the temperature of the battery 12 exceeds a predetermined upper limit and the water temperature is below the temperature of the battery 12, and when the temperature of the battery is below a predetermined lower limit and the water temperature exceeds the temperature of the battery 12. Furthermore, heat exchange between water and the battery 12 is restricted in at least one of the following cases: when the temperature of the battery 12 exceeds the upper limit and the water temperature exceeds the temperature of the battery 12, and when the temperature of the battery 12 is below the lower limit and the water temperature is below the temperature of the battery 12. This makes it easier to maintain the battery temperature within a temperature range suitable for maintaining performance and extending lifespan. As a result, the output of the battery 12 can be stabilized and the lifespan of the battery 12 can be extended. Thus, the performance of the electric marine propulsion system 1 can be improved.

[0047] Furthermore, the marine propulsion system 1 of this embodiment includes a power converter 14 that converts the power of the battery 12 and supplies it to the motor 16. The temperature-controlled water flow path 30 also includes a second path R2 that bypasses the first heat exchange section 46 and passes through a second heat exchange section 48 that is heat-exchangeable with the power converter 14. The path switching section 38 allows water to flow to the second path R2 in a restricted state. As a result, water that is no longer used for heat exchange with the battery 12 can be used to cool the power converter 14, thereby further improving the performance of the marine propulsion system 1.

[0048] Furthermore, in this embodiment, the first path R1 passes through the second heat exchange section 48 in addition to the first heat exchange section 46. This ensures that the power converter 14 is always cooled regardless of whether the external water passes through the first path R1 or the second path R2. Thus, the performance of the marine propulsion system 1 can be further improved.

[0049] The embodiments of this disclosure have been described in detail above. The embodiments described above are merely examples of how to implement this disclosure. The content of the embodiments does not limit the technical scope of this disclosure, and many design changes, such as changes, additions, and deletions of components, are possible as long as they do not deviate from the idea of ​​this disclosure as defined in the claims. A new embodiment with design changes will have the effects of both the combined embodiment and the variation. In the embodiments described above, the content in which such design changes are possible is emphasized with notations such as "in this embodiment" or "in this embodiment," but design changes are also permitted even if there are no such notations. Any combination of the above components is also valid as an embodiment of this disclosure. The hatching applied to the cross-section in the drawings does not limit the material of the object to which the hatching is applied.

[0050] Figure 4 is a schematic diagram showing the flow path structure of temperature-controlled water in a modified marine propulsion system 1. As shown in Figure 4, in the modified marine propulsion system 1, a second heat exchange section 48 is located upstream of the pilot water outlet 50 in the first path R1 and the second path R2. The power converter 14 and the motor 16 are connected to this second heat exchange section 48 in a heat exchange manner. In this case, for example, the second heat exchange section 48 is composed of a part of the second flow path section 30b. The power converter 14 and the motor 16 are housed in the upper housing 2.

[0051] By positioning the second heat exchanger 48 upstream of the pilot water outlet 50, the amount of temperature-controlled water passing through the second heat exchanger 48 can be increased compared to when it is positioned downstream. Therefore, the cooling efficiency of the power converter 14 and the motor 16 can be improved.

[0052] The embodiments may be specified by the items described below. [Item 1] A motor (16) that drives the thruster (18), A battery (12) that supplies power to the motor (16), A temperature-controlled water channel (30) through which water from the outside of the hull (100) flows, including a first path (R1) that passes through a first heat exchange section (46) that is heat-exchangeable to a battery (12), A path switching unit (38) that can switch between an allowable state that permits the flow of water to the first path (R1) and a restrictive state that restricts said flow, A first temperature sensor (40) detects the temperature of the battery (12), A second temperature sensor (42) for detecting the water temperature, The system includes a control unit (44) that controls the path switching unit (38) based on the battery temperature detected by the first temperature sensor (40) and the water temperature detected by the second temperature sensor (42), The control unit (44) is When the battery temperature exceeds a predetermined upper limit and the water temperature is below the battery temperature, and when the battery temperature is below a predetermined lower limit and the water temperature exceeds the battery temperature, the path switching unit (38) is controlled to take an acceptable state in at least one of these cases. A marine propulsion system (1) that controls a route switching unit (38) to enter a restricted state in at least one of the following cases: when the battery temperature exceeds an upper limit and the water temperature exceeds the battery temperature, and when the battery temperature is below a lower limit and the water temperature is below the battery temperature. [Item 2] The marine propulsion system (1) includes a power converter (14) that converts power from a battery (12) and supplies it to a motor (16). The temperature-controlled water flow path (30) includes a second path (R2) that does not pass through the first heat exchange section (46) but passes through the second heat exchange section (48) which is heat-exchangeable and connected to the power converter (14). The route switching section (38) is a ship propulsion device (1) as described in item 1, which allows water to flow to the second route (R2) in a restricted state. [Item 3] The first path (R1) is the ship propulsion system (1) described in item 2, passing through the second heat exchange section (48). [Item 4] A method for controlling the temperature of a battery (12) mounted on a ship's propulsion system (1), When the temperature of the battery (12) exceeds a predetermined upper limit and the temperature of the water outside the hull (100) is less than the temperature of the battery (12), and when the temperature of the battery (12) is less than a predetermined lower limit and the temperature of the water exceeds the temperature of the battery (12), heat exchange is performed between the water and the battery (12). A method for regulating the temperature of a battery (12), which includes restricting heat exchange in at least one of the following cases: when the temperature of the battery (12) exceeds an upper limit and the temperature of the water exceeds the temperature of the battery (12), and when the temperature of the battery (12) is below a lower limit and the temperature of the water is below the temperature of the battery (12). [Explanation of Symbols]

[0053] 1 Marine propulsion system, 12 Battery, 14 Power converter, 16 Motor, 18 Propulsion unit, 30 Temperature-controlled water flow path, 38 Path switching unit, 40 First temperature sensor, 42 Second temperature sensor, 44 Control unit, 46 First heat exchange unit, 48 Second heat exchange unit, 100 Hull, R1 First path, R2 Second path.

Claims

1. A motor that drives the thruster, A battery that supplies power to the motor, A temperature-controlled water channel through which water from outside the hull flows, including a first path that passes through a first heat exchange unit connected to the battery in a heat exchange manner, A path switching unit capable of switching between an allowable state that permits the flow of water to the first path and a restrictive state that restricts the flow, A first temperature sensor for detecting the temperature of the battery, A second temperature sensor for detecting the temperature of the water, A control unit controls the path switching unit based on the battery temperature detected by the first temperature sensor and the water temperature detected by the second temperature sensor, The system includes a power converter that converts the power of the battery and supplies it to the motor, The control unit, When the battery temperature exceeds a predetermined upper limit and the water temperature is less than the battery temperature, and when the battery temperature is less than a predetermined lower limit and the water temperature exceeds the battery temperature, the path switching unit is controlled to take the permitted state, When the battery temperature exceeds the upper limit and the water temperature exceeds the battery temperature, and when the battery temperature is below the lower limit and the water temperature is below the battery temperature, the path switching unit is controlled to enter the restricted state in at least one of these cases. The temperature-controlled water flow path includes a second path that does not pass through the first heat exchange unit but passes through a second heat exchange unit that is heat-exchangeable and connected to the power converter, The route switching unit allows the flow of water to the second route in the restricted state. Marine propulsion system.

2. The first path passes through the second heat exchange section, The ship propulsion device according to claim 1.

3. A method for controlling the temperature of a battery installed in a ship's propulsion system, The aforementioned marine propulsion system comprises a motor for driving the propulsion unit, a battery for supplying power to the motor, and a power converter for converting the power from the battery and supplying it to the motor. When the temperature of the battery exceeds a predetermined upper limit and the temperature of the water outside the hull is less than the temperature of the battery, and when the temperature of the battery is less than a predetermined lower limit and the temperature of the water exceeds the temperature of the battery, heat exchange is performed between the water and the battery. When the temperature of the battery exceeds the upper limit and the temperature of the water exceeds the temperature of the battery, and when the temperature of the battery is below the lower limit and the temperature of the water is below the temperature of the battery, the heat exchange is restricted in at least one of these cases. The following includes performing heat exchange between the water and the power converter while the aforementioned restrictions are in place: How to adjust the battery temperature.

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