Patent Description:
<CIT> discloses a flight vehicle that stores power generated by a solar panel in a battery and flies by using power of the battery or provides a wireless communication service. <CIT> describes a vehicle comprising: a body having a skin; a heat source; and a thermal management system. The thermal management system comprises: a heat pipe comprising: an evaporator end and a condenser end; a vapour arranged to flow from the evaporator end to the condenser end; and a working fluid arranged to flow from the condenser end to the evaporator end, wherein the heat pipe is arranged such that the evaporator end is arranged in proximity to the heat source to absorb heat from the heat source; and one or more heat exchangers arranged in proximity to the condenser end and integrated with the skin.

Embodiments of the invention are described in the dependent claims. An embodiment of the present invention provides a flight vehicle. The flight vehicle includes a wing unit. The flight vehicle includes a main body unit. The flight vehicle includes a battery that is arranged in the wing unit. The flight vehicle includes a payload that is arranged in the main body unit and that includes at least any of electronic equipment or a control motor. The flight vehicle includes a radiator. The flight vehicle includes a heat pipe that exchanges heat between the battery, the payload, and the radiator and that has a check valve which causes a hydraulic fluid to be circulated to transfer the heat of the battery to the payload and the radiator.

The heat pipe has a battery corresponding portion that corresponds to the battery. The heat pipe has a radiator corresponding portion that corresponds to the radiator. The heat pipe has a payload corresponding portion that corresponds to the payload. The heat pipe has a first circulation portion that extends from the battery corresponding portion, branches at a branch unit, and is connected to each of the radiator corresponding portion and the payload corresponding portion. The heat pipe has a second circulation portion that extends from the payload corresponding portion and is connected to the radiator corresponding portion. The heat pipe has a third circulation portion that extends from the radiator corresponding portion and is connected to the battery corresponding portion. The check valve may be positioned in the third circulation portion. The flight vehicle may include a valve that is arranged between the branch unit and the radiator corresponding portion in the first circulation portion and that is closed when a temperature of the payload is lower than a predetermined temperature threshold value, and is opened when the temperature of the payload is higher than the temperature threshold value. The valve may be a thermostatic valve. The flight vehicle may include a valve control unit that controls the valve to close the valve when the temperature of the payload is lower than a predetermined temperature threshold value, and to open the valve when the temperature of the payload is higher than the temperature threshold value. The payload corresponding portion may have a folded shape. The flight vehicle may include an air intake unit that is formed at a position corresponding to the battery on a front side of the wing unit; a heat sink unit that is arranged for the battery and cools the battery by air which flows in from the air intake unit and that includes a ventilation unit having a shape widening from the front side toward a rear side; and an exhaust unit that is formed at a position corresponding to the battery on the rear side of the wing unit and that exhausts air which flows out from the heat sink unit. The radiator may be positioned to be higher than the payload, and the battery may be positioned to be higher than the radiator. The battery corresponding portion may have a folded shape. The radiator corresponding portion may have a folded shape. The flight vehicle may function as a stratospheric platform.

Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to claims.

<FIG> schematically shows an example of a HAPS <NUM>. The HAPS <NUM> may be an example of a flight vehicle. The HAPS <NUM> may function as a stratospheric platform. While flying in a stratosphere, the HAPS <NUM> forms a feeder link <NUM> with a gateway <NUM> on the ground, and forms a wireless communication area <NUM> on the ground.

The HAPS <NUM> includes a main body unit <NUM>, a propeller <NUM>, a wing unit <NUM>, and a solar panel <NUM>. Power generated by the solar panel <NUM> is stored in a battery arranged in the wing unit <NUM>. The power stored in the battery is used by each configuration in the HAPS <NUM>.

A payload is arranged in the main body unit <NUM>. The payload may include electronic equipment. For example, the payload includes a control apparatus that controls flight and a communication of the HAPS <NUM>. The payload may also include a control motor.

The control apparatus controls the flight of the HAPS <NUM>, for example, by controlling a rotation of the propeller <NUM>, an angle of a flap or an elevator, or the like. The control apparatus may manage various types of sensors included in the HAPS <NUM>. Examples of sensors include a positioning sensor such as a GPS sensor, a gyro sensor, an acceleration sensor, and the like. The control apparatus may manage a location, a posture, a movement direction, and a movement speed of the HAPS <NUM> by outputs of the various types of sensors.

The control apparatus may use, for example, a FL (Feeder Link) antenna to form the feeder link <NUM> with the gateway <NUM>. The control apparatus may access a network <NUM> via the gateway <NUM>. The control apparatus may communicate with a management apparatus <NUM> connected to the network <NUM>.

The control apparatus may transmit various pieces of information to the management apparatus <NUM>. For example, the control apparatus transmits telemetry information to the management apparatus <NUM>. The telemetry information may include location information of the HAPS <NUM>. The location information may indicate a three-dimensional location of the HAPS <NUM>. The telemetry information may include posture information of the HAPS <NUM>. The posture information may indicate a pitch, a roll, and a yaw of the HAPS <NUM>. The telemetry information may include movement direction information indicating the movement direction of the HAPS <NUM>. The telemetry information may include movement speed information indicating the movement speed of the HAPS <NUM>.

In addition, the control apparatus uses, for example, an SL (Service Link) antenna to form the wireless communication area <NUM> on the ground. The control apparatus uses the SL antenna to form a service link with a user terminal <NUM> on the ground.

The user terminal <NUM> may be any communication terminal as long as the user terminal <NUM> is able to communicate with the HAPS <NUM>. The user terminal <NUM> is, for example, a mobile phone such as a smartphone. The user terminal <NUM> may be a tablet terminal, a PC (Personal Computer), and the like. The user terminal <NUM> may be a so-called loT (Internet of Things) device. The user terminal <NUM> may include anything that corresponds to a so-called loE (Internet of Everything).

The HAPS <NUM> relays a communication between the network <NUM> and the user terminal <NUM>, for example, via the feeder link <NUM> and the service link. The HAPS <NUM> may provide the wireless communication service to the user terminal <NUM> by relaying the communication between the user terminal <NUM> and the network <NUM>.

The network <NUM> includes a mobile communication network. The mobile communication network may conform to any of the <NUM> (3rd Generation) communication system, the LTE (Long Term Evolution) communication system, the <NUM> (5th Generation) communication system, and the <NUM> (6th Generation) communication system and the communication system of the subsequent generation. The network <NUM> may include the Internet.

For example, the HAPS <NUM> transmits data received from the user terminal <NUM> in the wireless communication area <NUM> to the network <NUM>. In addition, for example, when the HAPS <NUM> receives data addressed to the user terminal <NUM> in the wireless communication area <NUM>, via the network <NUM>, the HAPS <NUM> transmits the data to the user terminal <NUM>.

The management apparatus <NUM> manages the HAPS <NUM>. The management apparatus <NUM> may communicate with the HAPS <NUM> via the network <NUM> and the gateway <NUM>. It should be noted that the management apparatus <NUM> may communicate with the HAPS <NUM> via a communication satellite. The management apparatus <NUM> may control the HAPS <NUM> by transmitting various types of instructions.

The management apparatus <NUM> may cause the HAPS <NUM> to circle over a target area such that the target area on the ground is covered by the wireless communication area <NUM>. For example, the HAPS <NUM> maintains the feeder link with the gateway <NUM> by adjusting a pointing direction of the FL antenna while flying in a circular orbit over the target area, and maintains the coverage of the target area by the wireless communication area <NUM> by adjusting a pointing direction of the SL antenna.

When a flow on an upper surface of a wing of an aircraft is taken in, it is possible to maintain a laminar flow, and an effect of increasing lift and reducing drag may be obtained; however, due to a problem of a weight increase or a complicated structure, in a typical structure of the aircraft, the intake of the flow is only partially adopted in some aircraft. The HAPS <NUM> according to the present embodiment contributes to solving the problem in the related art by taking in air from a front edge portion of the wing unit <NUM>, heating and expanding the air which is taken in, by exhaust heat of the battery, and accelerating the air to exhaust the air from a rear edge portion of the wing unit <NUM>, thereby preventing peeling and maintaining the laminar flow. As a specific example, in the HAPS <NUM> according to the present embodiment, as a front edge panel structure obtained by a process of forming innumerable minute openings by laser beam machining, an air intake unit takes in a boundary layer by a negative pressure of a rear portion to slow down the peeling. Then, by a structure of a heat sink that is provided on an upper portion of the battery and that has a shape of a harmonica in which a cross sectional area increases, an introduced atmosphere cools the battery, and the atmosphere which is taken in is caused to be heated, expanded, and accelerated. In a structure of the present invention, for a last part, through an exhaust unit that includes a nozzle for reducing the cross sectional area to increase a flow velocity, the atmosphere accelerated by the heat sink is further accelerated and discharged to prevent the peeling.

<FIG> schematically shows an example of a structure of a wing unit <NUM> of the HAPS <NUM>. <FIG> illustrates a case where eight batteries <NUM> are arranged in the wing unit <NUM>; however, the number of batteries <NUM> is not limited to this, and may be another number. In order to keep a weight balance as a whole, it may be desirable to arrange the same number of batteries <NUM> on a right wing side and a left wing side to be symmetrical. It should be noted that in the example shown in <FIG>, the HAPS <NUM> includes a plurality of batteries <NUM>; however, the HAPS <NUM> may include only one battery <NUM>.

The wing unit <NUM> may include an air intake unit <NUM> formed at a position corresponding to the battery <NUM> on a front side. The air intake unit <NUM> is arranged, for example, at the front edge portion of the wing unit <NUM>. The air intake unit <NUM> has, for example, a plurality of openings. The air intake unit <NUM> has a large number of minute openings formed, for example, by the laser beam machining.

The wing unit <NUM> includes an exhaust unit <NUM> formed at a position corresponding to the battery <NUM> on a rear side. The exhaust unit <NUM> is arranged, for example, between a main wing <NUM> and a movable wing <NUM> of the wing unit <NUM>.

The wing unit <NUM> may include a plurality of air intake units <NUM> and a plurality of exhaust units <NUM> that respectively correspond to the plurality of batteries <NUM>, as shown in <FIG>.

<FIG> schematically shows a cross sectional view of the wing unit <NUM> of the HAPS <NUM>. The wing unit <NUM> includes the main wing <NUM>, and the movable wing <NUM> connected to the main wing <NUM> via a hinge <NUM>. The wing unit <NUM> may include a heat sink unit <NUM> that is arranged for the battery <NUM> and that cools the battery <NUM> by the air which flows in from the air intake unit <NUM>. The heat sink unit <NUM> may have a shape corresponding to a shape of the battery <NUM>. For example, when an upper surface of the battery <NUM> has a rectangular shape, a lower surface of the heat sink unit <NUM> may have a rectangular shape with the same size as that of the upper surface of the battery <NUM>.

A width of the air intake unit <NUM> may be the same as a width of the heat sink unit <NUM>. The width of the air intake unit <NUM> may be narrower, or may be wider than the width of the heat sink unit <NUM>.

A width of the exhaust unit <NUM> may be the same as the width of the heat sink unit <NUM>. The width of the exhaust unit <NUM> may be narrower, or may be wider than the width of the heat sink unit <NUM>.

The heat sink unit <NUM> has a ventilation unit <NUM> having a shape widening from the front side toward the rear side. The ventilation unit <NUM> may have a shape which increases in height from the front side toward the rear side. This makes it possible to heat, expand, and accelerate the air which is taken in, while cooling the battery <NUM>.

The heat sink unit <NUM> has, for example, a harmonica shape. The heat sink unit <NUM> having the harmonica shape makes it possible for the heat of the battery <NUM> to be efficiently exhausted without a severe obstruction of a flow of the air which flows in from the air intake unit <NUM> and is exhausted from the exhaust unit <NUM>. It should be noted that the heat sink unit <NUM> may have a hollow structure rather than the harmonica shape.

The air intake unit <NUM>, the heat sink unit <NUM>, and the exhaust unit <NUM> are connected. The exhaust unit <NUM> exhausts the air which flows out from the heat sink unit <NUM>, to an outside of the wing unit <NUM>. The air intake unit <NUM> takes in a laminar boundary layer on the front side of the wing unit <NUM> by the negative pressure of the rear portion. It is possible to take in the laminar boundary layer, and slow down the peeling of the laminar flow, and it is possible to maintain the laminar flow, and increase the lift and reduce the drag.

In this way, by adopting the structure in which the negative pressure of the rear portion is applied to the air intake unit <NUM>, it is possible to take in the laminar boundary layer without using a plasma actuator or the like. When the plasma actuator is used, very high power is necessary and the total weight increases. With the structure of the wing unit <NUM> according to the present embodiment, it is possible to reduce power consumption in comparison with a case where the plasma actuator is used, and it is possible to contribute to a reduction of the total weight of the HAPS <NUM>.

The exhaust unit <NUM> may have a shape which narrows from the front side toward the rear side. The exhaust unit <NUM> has, for example, a shape which decreases in height from the front side toward the rear side. In this way, by the exhaust unit <NUM> having a structure in which the cross sectional area decreases from the front side toward the rear side, it is possible to increase, for the exhaust, the flow velocity of the air from the heat sink unit <NUM>.

The exhaust unit <NUM> may realize the exhaust along an upper surface of the movable wing <NUM> as illustrated in <FIG>. The exhaust unit <NUM> has an exhaust port, for example, between the main wing <NUM> and the hinge <NUM>. The exhaust unit <NUM> generates propulsion power for the HAPS <NUM> by the exhaust and attracts the laminar boundary layer on the rear side of the wing unit <NUM>.

The air which flows from the heat sink unit <NUM> to the exhaust unit <NUM> is heated, expanded, and accelerated by the heat sink unit <NUM> as described above, and can be further accelerated by the exhaust unit <NUM>, which makes it possible to contribute to the propulsion power of the HAPS <NUM>, and makes it possible to contribute to preventing the peeling of the laminar boundary layer on the rear side of the wing unit <NUM>.

<FIG> schematically shows an example of a heat pipe <NUM> included in the HAPS <NUM>. The heat pipe <NUM> exchanges the heat between a payload <NUM>, the battery <NUM>, and a radiator <NUM>. The radiator <NUM> is positioned to be higher than the payload <NUM>, and the battery <NUM> is positioned to be higher than the radiator <NUM>.

The heat pipe <NUM> has a check valve <NUM> that causes a hydraulic fluid to be circulated to transfer the heat of the battery <NUM> to the payload <NUM> and the radiator <NUM>. As the hydraulic fluid, a CFC substitute, water, and the like may be adopted similar to a case of an existing heat pipe; however, a selection may be appropriately performed according to an environment in which the flight vehicle flies.

The radiator <NUM> may be arranged in the main body unit <NUM> as shown in <FIG>. The radiator <NUM> may be arranged outside the main body unit <NUM>.

The heat pipe <NUM> may be configured to heat and keep the payload <NUM> to be warm in a situation in which the payload <NUM> is at a low temperature, such as while the HAPS100 is flying at night, while the HAPS100 moves to a location where the wireless communication area <NUM> is deployed, or while the HAPS100 is flying as a backup vehicle. The heat pipe <NUM> may be configured to cool the battery <NUM> and the payload <NUM> in a situation in which the power consumption is high, such as during daytime flight and prime time flight of the HAPS <NUM>.

<FIG>, <FIG>, and <FIG> are illustrations for describing heat circulations by the heat pipe <NUM>. <FIG> schematically shows how the hydraulic fluid circulates in a case where the payload <NUM> is at a low temperature. <FIG> schematically shows how the hydraulic fluid circulates in a case where the payload <NUM> is at a suitable temperature. <FIG> schematically shows how the hydraulic fluid circulates in a case where the payload <NUM> is at a high temperature.

The heat pipe <NUM> includes a battery corresponding portion that corresponds to the battery <NUM>, a radiator corresponding portion that corresponds to the radiator <NUM>, and a payload corresponding portion that corresponds to the payload <NUM>. The battery corresponding portion may have a folded shape so as to contact more parts of the battery <NUM> to efficiently exchange the heat of the battery <NUM>. The radiator corresponding portion may have a folded shape so as to contact more parts of the radiator <NUM> to efficiently dissipate the heat to the radiator <NUM>. The payload corresponding portion may have a folded shape so as to contact more parts of the payload <NUM> to efficiently exchange the heat of the payload <NUM>.

The heat pipe <NUM> may include a first circulation portion <NUM> that extends from the battery corresponding portion, branches at a branch unit <NUM>, and is connected to each of the radiator corresponding portion and the payload corresponding portion; a second circulation portion <NUM> that extends from the payload corresponding portion and is connected to the radiator corresponding portion; and a third circulation portion <NUM> that extends from the radiator corresponding portion and is connected to the battery corresponding portion. The check valve <NUM> is positioned in the third circulation portion <NUM>.

The heat pipe <NUM> has a valve <NUM> that is arranged between the branch unit <NUM> and the radiator corresponding portion in the first circulation portion <NUM> and that is closed when the temperature of the payload <NUM> is lower than a predetermined temperature threshold value, and is opened when the temperature of the payload <NUM> is higher than the temperature threshold value. The temperature threshold value may be, for example, <NUM>. The temperature threshold value may be able to be set to any threshold value, or may be changeable. The valve <NUM> may be a thermostatic valve. It should be noted that the HAPS <NUM> may also include the valve <NUM> that is not the thermostatic valve; and a valve control unit that closes the valve <NUM> when the temperature of the payload <NUM> is lower than a predetermined temperature threshold value and that opens the valve <NUM> when the temperature of the payload <NUM> is higher than the temperature threshold value.

<FIG> illustrates a state in which the temperature of payload <NUM> is lower than a predetermined temperature threshold value and the valve <NUM> is closed. The temperature of the payload <NUM> may be, for example, approximately from -<NUM> to <NUM>. When there is no check valve <NUM>, the hydraulic fluid which has become a gas, stays near the battery <NUM>; however, the heat pipe <NUM> according to the present embodiment has the check valve <NUM>, so that the hydraulic fluid circulates in order from the battery <NUM> to the payload <NUM>, from the payload <NUM> to the radiator <NUM>, and from the radiator <NUM> to the battery <NUM>, and cools the battery <NUM> and the heat is exhausted by the payload <NUM>.

<FIG> illustrates a case where the temperature of the payload <NUM> is a suitable temperature. The temperature threshold value is set to be lower than the suitable temperature, and when the temperature of payload <NUM> is the suitable temperature, the valve <NUM> is in an open state. The temperature threshold value may be, for example, <NUM>, as described above, and the valve <NUM> is opened when the temperature of payload <NUM> exceeds <NUM>. The suitable temperature for the payload <NUM> may be approximately from <NUM> to <NUM>. When the temperature of the payload <NUM> is the suitable temperature, almost no hydraulic fluid circulates to a payload <NUM> side by a circulation resistance due to the structure of the payload corresponding portion of the heat pipe <NUM>, and the hydraulic fluid circulates in order from the battery <NUM> to the radiator <NUM>, and from the radiator <NUM> to the battery <NUM>. In this manner, only the battery <NUM> is cooled and the heat is exhausted by the radiator <NUM>.

<FIG> illustrates a case where the temperature of the payload <NUM> is a high temperature. The high temperature of the payload <NUM> may be, for example, <NUM> or higher. The valve <NUM> is in an open state. The temperature of the payload <NUM> is the high temperature, and thus the circulation of the hydraulic fluid occurs also on the payload <NUM> side. The hydraulic fluid circulates in order from the battery <NUM> to the radiator <NUM>, and from the radiator <NUM> to the battery <NUM>, and circulates in order from the payload <NUM> to the radiator <NUM> via the branch unit <NUM>, and from the radiator <NUM> to the payload <NUM>. In this manner, the payload <NUM> and the battery <NUM> are cooled, and the heat is exhausted by the radiator <NUM>.

<FIG> schematically shows an example of a structure of a payload corresponding portion of the heat pipe <NUM>. The payload corresponding portion may have a folded structure, as illustrated in <FIG>. By the payload corresponding portion having the folded structure, a portion that contacts the payload <NUM> increases, and it is possible to enhance the efficiency of the heat exchange. In addition, in comparison with the first circulation portion <NUM>, the second circulation portion <NUM>, and the third circulation portion <NUM>, it is possible to increase the resistance through which the hydraulic fluid passes, and when the payload <NUM> reaches a suitable temperature, it is possible for the hydraulic fluid not to circulate to the payload corresponding portion. The battery corresponding portion of the heat pipe <NUM> may also have a structure similar to the structure shown in <FIG>.

<FIG> schematically shows an example of a structure of a radiator corresponding portion of the heat pipe <NUM>. As illustrated in <FIG>, the radiator corresponding portion has a structure that branches at an inlet portion from the first circulation portion <NUM> and that is connected to each of the second circulation portion <NUM> and the third circulation portion <NUM>, and may have a structure in which each connection portion is folded. By having such a structure, in a case where the payload <NUM> is at a high temperature, it is possible to cause the hydraulic fluid to circulate in order from the battery <NUM> to the radiator <NUM>, and from the radiator <NUM> to the battery <NUM>, and to circulate in order from the payload <NUM> to the radiator <NUM> via the branch unit <NUM>, and from the radiator <NUM> to the payload <NUM>. In addition, by having the folded structure, a portion that contacts the radiator <NUM> increases, and it is possible to enhance the efficiency of the heat exchange.

A temperature management control of the payload in the HAPS <NUM> in a stratospheric environment is an important and very difficult task. Electrical equipment, the control motor, and the like may not operate at a low temperature, and it requires electric power to be equipped with a heater for heating, which increases the weight. In addition, when a heat insulation structure is adopted, conversely, there occurs a problem that cooling becomes difficult. On the other hand, even when cooling is desired, a thin atmosphere makes it difficult for the heat to be naturally dissipated, and only a temperature of a unit at a high temperature becomes a very high temperature.

In the HAPS <NUM> according to the present embodiment, for example, the payload <NUM> that is desired to maintain a suitable temperature by being warmed and being cooled, and the battery <NUM> that is a portion at a high temperature and is desired to be cooled, are connected to each other by the heat pipe <NUM> having the check valve <NUM>. Then, the radiator <NUM> and the valve <NUM> (the thermostatic valve) are arranged in between, and the valve <NUM> is opened and closed according to the temperature, and a flow mode of the hydraulic fluid in the valve <NUM> is changed to constantly cool the battery <NUM>, and the warming and the cooling are performed to keep the payload <NUM> at the suitable temperature. This makes it possible to contribute to automatically maintaining the suitable temperature only by a force of the fluid without consuming the electric power, which enables an effective temperature management.

In the embodiment described above, the HAPS <NUM> is given as an example of the flight vehicle, but the present invention is not limited to this. The flight vehicle may be any flight vehicle as long as the battery and the payload are mounted on the flight vehicle.

While the embodiment of the present invention has been described, the technical scope of the invention is not limited to the above-described embodiment. It is apparent to persons skilled in the art that various alterations and improvements can be added to the above described embodiments. It is also apparent from the description of the claims that embodiments added with such alterations or improvements can be included in the technical scope of the present invention.

The operations, procedures, steps, and stages of each process performed by an apparatus, system, program, and method shown in the claims, embodiments, or diagrams can be performed in any order as long as the order is not indicated by "prior to," "before," or the like and as long as the output from a previous process is not used in a later process. Even if the process flow is described using phrases such as "first" or "next" in the claims, embodiments, or diagrams, it does not necessarily mean that the process must be performed in this order.

Claim 1:
A flight vehicle (<NUM>) comprising:
a wing unit (<NUM>);
a main body unit (<NUM>);
a battery (<NUM>) that is arranged in the wing unit (<NUM>);
a payload (<NUM>) that is arranged in the main body unit (<NUM>) and that includes at least any of electronic equipment or a control motor;
a radiator (<NUM>); and
a heat pipe (<NUM>) that exchanges heat between the battery (<NUM>), the payload (<NUM>), and the radiator (<NUM>) and that has a check valve (<NUM>) which causes a hydraulic fluid to be circulated to transfer the heat of the battery (<NUM>) to the payload (<NUM>) and the radiator (<NUM>), wherein
the heat pipe (<NUM>) has
a battery corresponding portion that corresponds to the battery (<NUM>),
a radiator corresponding portion that corresponds to the radiator (<NUM>),
a payload corresponding portion that corresponds to the payload (<NUM>),
characterized in that the heat pipe (<NUM>) has a first circulation portion (<NUM>) that extends from the battery corresponding portion, branches at a branch unit (<NUM>), and is connected to each of the radiator corresponding portion and the payload corresponding portion,
a second circulation portion (<NUM>) that extends from the payload corresponding portion and is connected to the radiator corresponding portion, and
a third circulation portion (<NUM>) that extends from the radiator corresponding portion and is connected to the battery corresponding portion.