High-altitude aerostat with large surface area

Abstract

A variable volume aerostat is comprised of a flat gas encapsulation member that is joined to a pilot aerostat body. The flat gas enclosure member is typically deployed by rotation of a cylindrical pilot airship or a take-up roller suspended below a pilot aerostat. In its stowed configuration, the flat gas envelope member is rolled, uninflated and relatively compact. When the invention rises to the high altitude, the lift gas expands from the pilot aerostat into the deployed flat gas encapsulation member. When fully deployed, the flat gas envelope member is self-supporting and has a horizontal surface area up to 100 times greater than a pilot aerostat. This is a major advantage in potential applications including directed solar radiation management (SRM) and on-board solar power generation.

Description

Technical Field

[0001] The present invention relates to a variable volume aerostat that can increase its horizontal area by up to about 100 times as it rises to high altitudes. It transports large areas of active layers to high altitudes, which are valuable in applications that interact with direct sunlight, such as directed solar geoengineering (also known as Solar Radiation Management (SRM)), airborne solar power generation, and climate adaptation. Background Art

[0002] Lighter-than-air vehicles, such as balloons or airships, collectively known as aerostats, are well suited for aerial applications that require long flight times with minimal energy consumption.

[0003] Airships can be non-rigid, semi-rigid, or rigid. Non-rigid airships, also called "blimps," are gas-enclosed structures that take on the shape of an airship when inflated to positive pressure. Semi-rigid airships have some rigid structure, but their overall shape is still determined by the positive pressure within the gas-enclosed structure. Rigid airships have a rigid frame supporting a fixed-shape skin, containing one or more gas-enclosed structures. Rigid airships are generally heavier, but are more rigid and less susceptible to gas leaks.

[0004] The most suitable atmospheric environment for long-duration aerostats is the lower stratosphere (NPL 2). In the stratosphere, the air is relatively stable most of the time, and a given wind or wind shear exerts a lower force because the air is less dense.

[0005] In order for an aerostat to maintain its lifting capacity as it ascends, its enclosure must continue to displace the same total mass of air. According to Boyle's Law, at constant temperature, the volume of lifting gas must increase inversely as pressure decreases with altitude.

[0006] In most existing high altitude aerostats, the gas enveloping member is partially filled with a lifting gas at the ground. As the aerostat rises, the lifting gas expands, increasing the volume of the gas enveloping member, thereby displacing a greater volume of air.

[0007] Most contemporary high altitude airship designs are of the semi-rigid type (NPL2), but modern materials and technology offer the potential for lightweight rigid airships that can reach stratospheric altitudes. As examples and not limitations, the rigid frame may be formed of inflatable tubes (PTL3) or a hybrid of circumferential inflatable rings and longitudinal carbon fiber skeletons (NPL3) or a mandrel truss with reinforcing rings (PTL12).

[0008] Rigid airships sometimes include internal structures such as "sub-airbags" (PTL5) for controlling buoyancy by actively changing the total volume of lifting gas. Deformable airships (PTL6, PTL11) are airships that can reconfigure their internal structures to change volume and surface area to a limited extent (e.g., "6-8 times") (PTL6).

[0009] Certain aerial applications require large surface areas. Airborne solar power (PTL1, PTL7, PLT10) requires large areas of photovoltaic cells at high altitudes. Some existing designs (PTL1) require complex structures that must be unrolled at ground level and deployed in fixed positions. Others (PLT10) require individual reflectors suspended by whatever wind force prevails.

[0010] Some forms of solar radiation management (SRM) require large areas of reflective surfaces in order to direct incoming solar radiation back into space. In existing designs (PTL2) for airborne SRM, non-buoyant reflective sheets are supported by one or more concentric expansion rings and attached support balloons.

[0011] Long-duration airships require solutions to minimize or repair leaks in gas-enclosing components, such as durable hulls [PTL8] or autonomous repair systems [PTL9]. Summary of the invention

[0012] The present invention is a novel variable volume aerostat, which is composed of a flat gas encapsulation member (102); it acts as an expansion volume for one or more aerostat bodies (104, 132, 136) attached thereto. The air chambers in these aerostat bodies are internally connected to the interior of the flat encapsulation member, so that the lifting gas can move between them.

[0013] The main innovation is the use of flat gas-enclosing members to provide the expansion volume required for ascent to high altitudes, and a flat surface with the largest possible area once deployed.

[0014] The present invention is a solution for exposing large surface areas to direct sunlight to support applications such as directional solar radiation management (SRM), airborne solar power generation, or localized climate adaptation.

[0015] Deploying at high altitudes both increases the intensity of incoming solar radiation and reduces the risk of damage from atmospheric disturbances.

[0016] In its stowed configuration, the flat gas containment member (102) is not inflated and is typically rolled or folded for compactness and portability. Unlike existing high altitude aerostats, the containment members of each interconnected aerostat body (104, 132, 136) can be fully filled with lifting gas at launch, maximizing ground lift capability.

[0017] As the present invention ascends, the flat gas-enclosing member gradually unfolds, and the lifting gas in each of the internally communicating aerostat bodies (104, 132, 136) expands into the flat gas-enclosing member.

[0018] In its deployed configuration at a target altitude, the flat gas-enclosing member (102) is filled with a lifting gas and has a balanced buoyancy. A depth-constraining structure (101), such as a rib, constrains the depth of the flat gas-enclosing member and determines its shape. The inflated flat gas-enclosing member is normally deployed in a nearly straight line between the two aerostat bodies. This shape can be maintained by relatively small tension.

[0019] In the preferred embodiment "retractable aerostat", each inter-connected aerostat body is an airship (104) which is cylindrical for most of its length. In its retracted configuration, an uninflated flat gas-enclosing member (102) is retracted around the cylindrical body of the inter-connected airship. As the retractable aerostat ascends and descends, each inter-connected airship rotates to cause the flat gas-enclosing member to unfold and retract.

[0020] In an alternative embodiment "Suspended Roller", one or more cylindrical reel rollers (131) are suspended below a non-rotating, interconnected aerostat body (132, 136). In the stowed configuration, an uninflated flat gas-enclosing member (102) is reeled around these reel rollers. A motor (134) rotates the reel rollers to unwind and reel the flat gas-enclosing member.

[0021] All forms of the invention are relatively compact and easy to handle in their stowed configuration, yet are capable of deploying a very large surface area aloft.

[0022] Examples of the present invention are designed to operate at specific target altitudes which may be up to about 25 km. The internal structure (101) within the flat gas enclosure member is normally designed to have balanced buoyancy along its length and width.

[0023] For SRMs, the surface of a flat, gas-enclosing member is covered with a high-albedo material or coating that reflects a significant portion of the incident solar radiation back into space.

[0024] For airborne solar power generation, the top surface of the flat gas-enclosed structure would be covered with flexible thin-film, UV-resistant photovoltaic cells.

[0025] The present invention may be ground tethered or autonomous, depending on the requirements of the particular application and the location in which it is deployed.

[0026] Technical issues

[0027] Solar radiation management applications require very large surface areas of materials that reflect solar radiation and remain in place over long time scales. Large non-buoyant surfaces (PTL2) will tend to sag downwards.

[0028] Airborne solar power generation requires large photovoltaic cell surface areas to be exposed for long periods of time to be economically viable.

[0029] Supporting these applications with lighter-than-air platforms requires maximizing the useful surface area delivered by a given volume of aerostat and delivering that surface to a sufficiently stable portion of the atmosphere.

[0030] The lowest risk environment for long duration applications is the lower stratosphere, which starts at altitudes above about 10 km in the high latitudes to about 20 km in the tropics (NPL2).

[0031] Existing stratospheric aerostat designs (NPL2) can only carry relatively small areas of non-buoyant surfaces aloft because they have little lifting capacity.

[0032] Shorter duration or periodic applications may sometimes be feasible at low altitudes, but the risk of damage from atmospheric disturbances must be managed.

[0033] By itself, a flat gas containment structure partially filled with lifting gas at the surface would be extremely heavy, fragile, difficult to deploy and operate, and difficult to recover.

[0034] The challenge in both applications is to deliver a lighter-than-air platform that exposes maximum surface area in a deployed configuration while aloft, while having a stowed configuration that is operationally feasible on the ground.

[0035] Solution to the problem

[0036] The proposal is a variable-volume hybrid aerostat system that is compact on the ground but can maximize its surface area as it rises to high altitudes.

[0037] The essential features of the present invention are as follows.

[0038] A flat gas containment structure (102) having a width of up to several thousand meters provides a large surface area. It is made of a lightweight material that is impermeable to the lifting gas. The depth of the flat gas containment structure is limited by depth restraining structures such as ribs to deliver a balancing buoyancy along its width.

[0039] The flat gas encapsulating member may have a single internal volume or be divided into a plurality of cells internally. It may be a single encapsulating member or may consist of a plurality of individual parallel strips.

[0040] One or more aerostat bodies connected to the flat gas enclosure provide ground lifting capability and a lifting gas reservoir. An air chamber in the aerostat body that is internally connected to the interior of the flat enclosure provides lifting gas, which expands into the flat gas enclosure when the system rises to a high altitude.

[0041] In its stowed configuration, at low altitude, the flat gas-enclosing member is uninflated and may be rolled or folded. The air chamber within each interconnected aerostat body (104, 132, 136) is typically completely filled with lifting gas. Since the flat gas-enclosing member contains little or no lifting gas, its weight is supported entirely by the net lifting capacity of each interconnected aerostat body.

[0042] As the invention ascends and ambient pressure decreases, lifting gas expands from each of the interconnected aerostat bodies (104, 132, 136) into the flattened gas-enclosing member (102).

[0043] In its deployed configuration at a target altitude, the flat gas-enclosing members (102) are fully unfolded and fully inflated, making them balanced buoyant and self-supporting. Lifting gas retained within each interconnected aerostat body (104, 132, 136) provides sufficient lift to support its payload.

[0044] The depth constraining structure (101) constrains the depth of the flat gas enclosing member (102). The flat gas enclosing member naturally adopts a horizontal position when the average depth across the cross section of the flat gas enclosing member is always equal to the lifting gas depth required to offset the weight of the flat gas enclosing member at the target height.

[0045] As shown in FIG. 12 , the internally connected aerostat body can be: at one end of the flat encapsulating member, i.e., a single connection layout; at both ends of the flat encapsulating member, a double connection layout; or in the middle of the flat encapsulating member, a central connection layout.

[0046] The maximum width of the flat gas-enclosing member (102) is mainly constrained by the mass per unit area of ​​the uninflated flat gas-enclosing member and the net lifting capacity of the internally connected aerostat body (104) at the ground.

[0047] Assume that the surface density of the flat envelope is σ, the buoyancy of the lifting gas during takeoff is b0, and the total internal volume of the connected aerostat is V a And the total mass is m a , the maximum area A of the flat encapsulating member is given by the following equation:

[0048]

[0049] Assume that the atmospheric pressure at takeoff is P S And the temperature is T S , the temperature at the ceiling altitude is T C , the pressure at the ceiling altitude P C This is derived from the following equation:

[0050]

[0051] The depth d of the flat encapsulating member at pressure P and temperature T is given by the following equation:

[0052]

[0053] Preferred features of the present invention are as follows.

[0054] To prevent tearing, the flat gas enclosure member is typically reinforced with strong and lightweight strap members or cable members (115).

[0055] The flat gas enveloping member may be divided into individual sections and lightweight tube members (122, 126) may be added along its width to accelerate the flow of lift gas. If made of a strong material, these lightweight tube members may also serve as reinforcement structures. The tube members may include active or passive valves to control the flow of lift gas.

[0056] In the deployed configuration, the flat gas-enclosing member (102) can be held in slight tension by thrusters (114) on the aerostat body (104, 132, 136), requiring a relatively small amount of power. The end tether members (111) can also sometimes provide this tension.

[0057] If desired, the length of the depth confining structures (101) can be varied to produce other shapes and configurations. Uneven spacing of the depth confining structures can help suppress standing waves in the flat gas enclosing member.

[0058] The invention can be autonomous or tethered by a lightweight tether member (111). There are a large number of possible autonomy options, from systems physically controlled by end tether members, systems controlled remotely to fully autonomous robotic systems.

[0059] Precise control of the aerostat bodies (104, 132, 136) is required to avoid excessive stress on the flat gas enclosure members and to avoid collisions between aerostat bodies. In a dual system, telescoping arm members extending inwardly from each aerostat body may also be used to manage separation during takeoff and landing.

[0060] Examples of autonomy include energy storage (112), propulsion (114) and control systems required to control position, rotation, containment tension, altitude, attitude and speed. Energy storage capacity is not always sufficient for night travel, but must be sufficient for controlling orientation and maintaining slight tension in containment.

[0061] All embodiments may feature additional buoyancy at the aerostat body or in the middle of the flat gas-enclosing member. Figure 7 As shown in , in the dual connection example, an additional central airship body (127) can be used to support the weight of the central tether member (111) or other centrally mounted hardware (such as solar cells (103)), and can also act as a compressible buffer between the two aerostat bodies at low altitudes.

[0062] In the preferred embodiment of the present invention, "retractable aerostat", each interconnected aerostat body is an airship (104) having a main body which is substantially cylindrical in shape so that the flat gas-enclosing member (102) can be retracted around the main body of the airship.

[0063] Each cylindrical airship (104) has a high degree of radial symmetry and a sufficiently strong internal structure to transmit torque from the longitudinal axis to the cylindrical surface.

[0064] As the "retractable aerostat" rises, controlled rotation of each cylindrical airship (104) gradually unfolds the flat gas-enclosing member (102), allowing lifting gas to expand therein.

[0065] As the retractable aerostat descends, reverse rotation causes the flat gas-enclosing member (102) to reel again around each cylindrical airship (104), squeezing lifting gas into the air chamber within the airship.

[0066] like Fig.11 As shown, the minimum altitude required to enter the lower stratosphere varies from about 10 km near the poles to as high as 20 km in the tropics. In the polar stratosphere in summer, the zonal winds are relatively low (NPL2) and the sun is in the sky for most of the day, although the solar altitude angle is low. This comprises the most feasible operating environment for medium-duration applications of the present invention.

[0067] Existing rigid airships have a ceiling well below 10 km, but advanced materials and novel designs, such as the incorporation of inflatable beams into the frame (PTL3, NPL3), make higher altitudes possible.

[0068] A rigid airship with a cylindrical body is easier to build than the traditional ellipsoidal design (NPL1).

[0069] Conventional semi-rigid airships have a rigid keel (NPL2) at the base of the encapsulation member. A semi-rigid cylindrical airship for the aerostat body has a rigid spine along its longitudinal axis. Unlike a rigid cylindrical airship, a semi-rigid cylindrical airship requires an air pump, valves and control system to maintain a positive internal pressure and external shape. A facility for pumping lift gas potentially enables the flat gas encapsulation member (102) to be fully deployed at any altitude.

[0070] In the autonomous version of the "retractable aerostat", the torque for rotation is applied by a counterweight (110) suspended on the longitudinal axis of the cylindrical airship (104) or a weighted railcar (117) that moves along a rack (118) that surrounds the surface (123) of the cylindrical airship.

[0071] In an alternative embodiment "suspended wind-up roll", the flat gas-enclosing member (102) is wrapped around a cylindrical wind-up roll (131) suspended below a conventional airship (132) or assembly of one or more non-rigid aerostats (136).

[0072] In the suspended reel, a gas tube member (116) is connected via a rotary joint (135) on the axis of the reel, which connects the air chamber in the internally connected aerostat to the flat gas encapsulation member. The motor (134) rotates the reel (131) to unfold and reel the flat gas encapsulation member (102).

[0073] In both SRM and solar power generation applications, it is desirable to maximize its interaction with incident sunlight. A key factor in this, especially at high latitudes, is the ability to point the enclosure directly toward the sun.

[0074] Some examples have the ability to move internal weights longitudinally to completely change the pitch of the airship. The flat enclosure may also include small movable weights or use pressure changes to passively or actively follow the pitch of the airship. These examples may change the pitch of the flat enclosure to face the sun when wind conditions permit.

[0075] Asymmetric or variable buoyancy in the aerostat bodies can be used to create a tilt along the width of the flat gas-enclosing member to allow the invention to reel in towards the sun. Asymmetric or variable buoyancy can also create a vertical offset between aerostat bodies at low altitudes, reducing the risk of collision.

[0076] In SRM applications, it is desirable to minimize interaction with the Earth's longwave radiation, especially during periods of darkness. This can be achieved by presenting as little surface area as possible to the ground.

[0077] Some examples of the invention are designed to be lowered and rolled up at night. Examples with full control over pitch and position can place the flat gas enclosure member (102) in a vertical position, facing sideways to the prevailing wind during darkness. Some examples can optionally fold up the flat gas enclosure member during darkness.

[0078] In SRM applications, the upper layer of the flat gas containment member (102) is selected to reflect as much solar radiation as possible back into space. To maximize the net impact on Earth radiation, the containment member material is also selected to maximize the permeability to Earth longwave radiation.

[0079] In SRM applications, the flat gas-enclosed structure can be relatively simple and inexpensive. To maximize the surface area transported by a more complex guided aerostat, the flat gas-enclosed structure can be disconnected from the guided aerostat at a target altitude and allowed to float freely in the atmosphere. The guided aerostat can then descend to refill with lifting gas and gather another flat enclosed structure. In this case, the flat enclosed structure can incorporate deeper areas or additional buoyancy at the ends to support the weight of the small thruster.

[0080] Beneficial effects of the present invention

[0081] The present invention maximizes the surface area of ​​the aerostat at a target altitude, increasing it by up to 100 times.

[0082] The present invention is relatively compact at low altitudes, enabling feasible operation and launch from the ground, and requiring only a relatively small storage space.

[0083] The present invention can transport very large radiation active layers such as photovoltaic films or high albedo surfaces to higher altitudes where sunlight is more intense and the atmosphere is more stable.

[0084] The present invention consists of two simple and well understood components - an aerostat body of relatively standard design and a flat gas containment member having a depth restraining structure.

[0085] The autonomous version of the present invention is relatively maneuverable at low altitudes and can fly to a target location before ascending to a target altitude.

[0086] The present invention can actively adjust its position, angle and shape to maximize its interaction with sunlight and minimize its interaction with the earth's longwave radiation.

[0087] The present invention is a viable platform for directional solar radiation management that can accurately reduce insolation in specific locations, such as those with high climate sensitivity, conservation issues, or challenges to human habitation.

[0088] The present invention is a viable platform for airborne solar power generation, particularly for locations lacking suitable or affordable land area, or for sun-following energy platforms.

[0089] Deployment at higher altitudes has several benefits for solar power generation. The intensity of solar radiation is increased because there is less atmosphere above the system to scatter or absorb it. At stratosphere altitudes, sunlight can be three times more intense than at ground level. Losses due to cloud cover are virtually eliminated. Low ambient temperatures also minimize heat losses in the photovoltaic cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] The drawings show the essential components of the invention at launch, during ascent or at a target operating altitude. None of these figures are drawn to scale. In particular, the relative width of the flat gas enveloping member is much smaller than in a real system.

[0091] [ Figure 1a ] shows a simplified plan view from above of a "retractable aerostat" in its retracted configuration, showing the connected airships (104) with their cylindrical bodies shielded by uninflated flat gas containment members (102) wrapped around them.

[0092] [ Figure 1b ] shows a simplified front cross-sectional view of a "retractable aerostat" in its retracted configuration, showing the circular cross-section of the connected aerostat (104), and the uninflated flat gas-enclosing member (102) wrapped around each cylindrical body.

[0093] [ Figure 2a ] shows a simplified plan view from above of a "retractable aerostat" in its deployed configuration, showing the airship (104) spaced apart with the inflated and balanced buoyant flat gas-enclosing structure (102) stretched between them.

[0094] [ Figure 2b] shows a simplified front cross-sectional view from above of the "retractable aerostat" in its deployed configuration, showing the circular cross-section of the airship (104) spaced apart with the inflated and balanced buoyant flat gas-enclosed members (102) extending between them.

[0095] [ Figure 2c ] shows a simplified cross-section of a flat gas enclosure member in its expanded configuration, showing the depth restraining structure (101) and the cable member (115).

[0096] [ Figure 2d ] shows a detailed view from above of a flat gas enclosure member in its deployed configuration, showing the depth restraining structure (101) and the cable member (115).

[0097] [ Figure 3a ] is a cross-sectional view of a connected airship (104) in a "retractable aerostat" showing an internal rotating device including a rotating support member (108), a suspension (109), a counterweight (110) and a flat gas-enclosing member (102) having a balanced buoyancy.

[0098] [ Figure 3b ] is a detailed view of the rotating support member, illustrating the electric motor (105) turning the large gear (107) attached to the central column beam member (106) of the airship.

[0099] [ Figure 4a ] is a front view of an airship (104) in a "retractable aerostat" with end tethers. The semi-elliptical end caps are illustrated by concentric circles. It shows an external rotating device, which includes a rotating support member (108), a suspension (109) and a counterweight (110) and a ground tether member (111) attached to the counterweight.

[0100] [ Figure 4b ] is a front view of an airship (104) connected in an autonomous "retractable aerostat", showing a multi-directional propulsion system including a tiltable thruster (114), a power storage device (112) and a power rotating member (113) connecting it to the suspension (109).

[0101] [ Figure 5 ] shows a view of a rack rotating device mechanism within the surface of an airship (123), consisting of a circular rack member (118), a guide rail (119) and a rail car (117).

[0102] [ Figure 6] shows a cross section through an unfolded flat gas containment member, comprising a rhombus cross-section tubular member with perforated internal facets. In the rolled-up section (121) of the containment member, the stacked tubular members (122) are located on top of a fixed tubular member (125) attached to the surface of an airship (123). The internal facets of the stacked tubular members (122) form a seal to each other. In the unfolded section (120) of the containment member, the exposed perforations in the internal facets of the separated tubular members (126) enable lift gas to flow from the air chamber within the airship (124) into that section of the containment member.

[0103] [ Figure 7 ] is a simplified front cross-sectional view of a "retractable aerostat" in its retracted configuration, featuring an attached central separated aerostat body. It shows an uninflated flat gas-enclosed structure (102) wrapped around each attached aerostat (104), and a partially inflated semi-rigid separated aerostat (127) supporting the weight of a solar cell (103) in the middle of the flat gas-enclosed structure.

[0104] [ Figure 8 ] shows a close-up front cross-section of a "suspended reel" in its stowed configuration. A cylindrical reel (131) is suspended below an attached aerostat (136) around which an uninflated flat gas-enclosing member (102) is reeled. A tube member (116) connects the interior volume of the attached aerostat to the flat gas-enclosing member via a swivel joint (135) on the reel axis. A motor (134) rotates the reel to unwind and reel in the flat gas-enclosing member.

[0105] [ Fig. 9 ] shows a front cross-sectional view of a "suspended wind-up roller" embodiment in its stowed configuration. The two end bodies (136) each include one or more aerostats. A flat gas-enclosing member (102) is wrapped around a cylindrical wind-up roller (131) suspended below the end bodies.

[0106] [ Fig.10 ] is a side view of a "suspended wind-up roller" embodiment showing one of two ellipsoidal airships (132) with three wind-up rollers (130) suspended beneath its keel (133).

[0107] [ Fig.11 ] is a schematic cross section of the summer hemisphere showing the approximate locations of the tropopause (140), the polar jet or "jet stream" (141), and the tropical jet stream (142). The dashed box (143) indicates the most accessible portion of the lower stratosphere.

[0108] [ Fig.12a] shows a "double connection" layout having two connected aerostat end bodies (150).

[0109] [ Figure 12b ] shows a "single connection" layout having one connected aerostat end body (150) and one separate end body (151).

[0110] [ Fig.12c ] shows a "three-connected" layout having two connected aerostat end bodies (150) and one centrally connected aerostat body (150).

[0111] [ Fig.12d ] shows a "center connection" layout with one connected aerostat end body (150) and two separate end bodies (151).

[0112] [ Fig.12e ] shows a "double connection" layout with two connected aerostat end bodies (150) and a central separated aerostat body (151). DETAILED DESCRIPTION

[0113] All embodiments may be used in autonomous or tethered configurations, may feature additional buoyancy, and may be applied to SRM, solar power generation, or other high surface area applications.

[0114] All embodiments may be formed in a range of different configurations of interconnected and disconnected aerostats, including by way of example and not limitation: Figures 12a to 12e Single, double, triple or center connection layout as shown in .

[0115] In the simplest embodiment, the flat enclosure member is not reeled in or out of the attached aerostat. It can be folded and then released during takeoff, or released in an open position during takeoff. In a smaller example of the simplest embodiment, the detached aerostat (151) can be excluded from the Figures 12a to 12e In this case, the gas pressure alone shapes the flat packaging component.

[0116] The preferred embodiment "retractable aerostat" is illustrated in a dual connection arrangement in Figures 1 to 4. In this embodiment, the aerostat body is an airship having a cylindrical body (104). The cylindrical portion of each inter-connected airship is used as a reel for retracting the uninflated flat gas-enclosing member (102) on the ground and for unfolding and retracting the flat gas-enclosing member as the invention ascends and descends.

[0117] Optional embodiment "suspended winding roller" in Figures 7 to 9The double connection layout is illustrated in the figure. The suspended wind-up roller embodiment enables the multi-purpose airship (132, 136) of existing design to deploy a relatively large surface. One or both ends of the flat gas-enclosing member (102) are wrapped around a cylindrical wind-up roller (131) suspended below one or more aerostats.

[0118] In the suspended reel embodiment, the interior of the aerostat enclosure member and the flat gas enclosure member are joined by a gas tube member (116), which is connected via a rotary joint (135) on the axis of the cylindrical reel. The motor (134) rotates the cylindrical reel to unwind and reel in the flat gas enclosure member. By way of example and not limitation, the cylindrical reel may be suspended from a balloon ( Fig. 9 ), ellipsoidal airship ( Fig.10 ) or below the "Two Balloon Airships" (PTL4).

[0119] Unlike a retractable aerostat, the reel (131) in a suspended reel does not support its own weight. The maximum length of a suspended reel is limited by its bending stiffness, since significant deflection along its length inhibits rotation.

[0120] Fig.10 A plurality of suspended wind-up rollers are shown suspended from the keel of a semi-rigid ellipsoidal airship (132). Opposing pairs of suspended wind-up rollers (130) deploy a plurality of parallel flat gas-enclosing members (102). The use of a plurality of in-line wind-up rollers enables the scheme to be expanded to large airship designs and achieves modular design.

[0121] Typical disadvantages of the suspended reel embodiment compared to the "reelable aerostat" embodiment are lower maximum height, reduced area of ​​the flat gas enclosure member and reduced ability to orient the surface of the flat gas enclosure member towards the sun.

[0122] Example

[0123] The airship-based examples in this section illustrate a range of possible applications, which are not intended to be exhaustive.

[0124] like Fig.11 As shown, the minimum altitude required to enter the lower stratosphere varies from about 10 km near the poles to as high as 20 km in the tropics. With proper active management, short-duration systems can be operated at much lower altitudes.

[0125] In the summer polar stratosphere, zonal winds are relatively low (NPL2) and the Sun is in the sky for much of the day, despite the low solar altitude angle. This encompasses the most feasible operating environment for medium to long duration applications.

[0126] The following information and assumptions were used to estimate the sizes and characteristics of the examples in this section:

[0127] The weight of an airship is roughly proportional to its surface area.

[0128] Rigid airships built with modern materials can carry 50% less weight than historical designs.

[0129] • The airship's gas-enclosing structure may occupy 90% of its interior volume.

[0130] ·Surface density less than 200g / m 2 High albedo surfaces or coatings are available.

[0131] Ultra-thin photovoltaic films are optimized for the solar spectrum at high altitudes, with a surface density of less than 200g / m 2 (NPL5).

[0132] The average surface density of the flat gas encapsulation member may be 500 g / m 2 ,based on

[0133] o 100 g / m2 on both surfaces of the flat gas encapsulation member 2 (NPL4)

[0134] οReinforced with carbon fiber yarn

[0135] οConnected by carbon fiber reinforcement components

[0136] ο250g / m 2 The radiation active layer

[0137] Examples all use Fig.12a The dual connection layout shown in

[0138] The weight of the ground tether members and any high voltage cables can be supported by additional buoyancy.

[0139] Table 1 lists approximate values ​​for key characteristics of various example categories (A through F) of reelable aerostats and suspended reel rolls based on the above information and assumptions and using equations (1) and (2) above.

[0140]

[0141] Example 1: Power Platform, a Class A system based on end tethers. Used to generate solar power where there is not enough land for ground-based solar panels. Operates during the day and returns to the ground at night and when strong winds are forecast. Small and rugged enough for routine ground handling and storage. Ultra-thin photovoltaic film layers covering 40,000m2 of flat gas-enclosed structures generate about 40MWh of energy per day in mid-latitudes.

[0142] Example 2: Pole Protector, based on an autonomous Class B system. This long-duration system is deployed in polar regions during the summer to shade the ocean near melting sea ice. It can help protect multi-season floating ice in areas such as the Beaufort Gyre, where about 3,000 systems can reduce net insolation by 1%. The system can be transported between hemispheres during the equinox.

[0143] Example 3: Hydrogen production platform based on Class B system. The retractable aerostat is tethered to a surface ship via a central airship. The electricity generated by the ultra-thin photovoltaic film is transmitted to the surface ship and used to electrolyze seawater. About 2,000 tons of hydrogen can be produced per month. The platform operates for 3 to 4 months near the poles during the summer and is transported between the hemispheres during the equinoxes.

[0144] Example 4: Interhemispheric Polar Protector based on Class C or Class D example systems. An autonomous long-duration solar reflector that stays in the stratosphere for years at a time. It spends most of its time above the summer pole, but is able to cross the equator during the equinoxes while remaining above the tropopause. Relatively safe from atmospheric disturbances, but still avoids large storms as much as possible due to the risk of upper atmospheric lightning, such as the phenomenon known as "blue jet".

[0145] Example 5: Glacier Shading Device, based on Example System Class E. Used to shade valley walls and debris-covered ice near high-latitude glaciers in summer. It can be transported to a remote location in components, assembled and inflated on site. Carbon fiber composite tether members hold it in place. In midsummer, it can reduce insolation in low-albedo regions by up to 400 MWh per day.

[0146] Example 6: An “artificial cloud” based on the Class F example system. Used to shade sensitive areas of land or ocean during the day. In mid-summer at mid-latitudes, it could reduce insolation in low-albedo areas by up to 2,000 MWh per day.

[0147] Industrial Applicability

[0148] The invention could be manufactured in the aerospace industry and used in the energy, geoengineering or climate adaptation industries.

[0149] Reference numerals list

[0150] The reference numerals used are as follows:

[0151] 101. Depth Constrained Structure

[0152] 102. Flat packaging component

[0153] 103. Solar cells

[0154] 104. Cylindrical airship

[0155] 105. Engines for rotating cylindrical airships

[0156] 106.Central column beam components of cylindrical airship

[0157] 107. Big Gear

[0158] 108. Rotating support member

[0159] 109. Suspension

[0160] 110. Counterweight

[0161] 111. Ground tether components

[0162] 112. Power storage device

[0163] 113. Power rotating components

[0164] 114.Thruster

[0165] 115. Rope and cable components

[0166] 116. Gas pipe components

[0167] 117. Railcar

[0168] 118.Rack rail

[0169] 119. Guide Rail

[0170] 120. Expanded section of flat gas encapsulation member

[0171] 121. Rolled-up section of encapsulating member

[0172] 122. Stacked perforated pipe members

[0173] 123. The Surface of an Airship

[0174] 124. Air chamber inside an airship

[0175] 125.Fixed tubular parts

[0176] 126.Separate perforated pipe components

[0177] 127. Semi-rigid aerostat body

[0178] 130. Suspended winding roller

[0179] 131.Cylindrical winding roller

[0180] 132. Ellipsoidal airship

[0181] 133. Keel

[0182] 134. Engine for rotating cylindrical winding roller

[0183] 135. Rotary joint

[0184] 136. A generic aerostat body with one or more aerostats added

[0185] 140. The approximate location of the tropopause

[0186] 141. Polar Jet Stream or "Jet Stream"

[0187] 142. Tropical Jet Stream

[0188] 143.Box representing the most accessible part of the lower stratosphere.

[0189] 150.Aerostats of any type with connections

[0190] 151. Any type of separate aerostat (may be optional in smaller systems)

[0191] Citation List

[0192] Patent Literature

[0193] PTL1: US133621015 Stratosphere tethered photovoltaic power platform

[0194] PTL2: US20200386970A1 Aerostatically Stabilized Atmospheric Reflector To Reduce Solar Irradiance

[0195] PTL3: WO2015065433A1 Rigid airship utilizing a rigid frame formed by high pressure inflated tubes

[0196] PTL4: US8061647B1 High altitude two balloon airship

[0197] PTL5: US5538203A Ballonet system for a lighter-than-air vehicle

[0198] PTL6: US20070034740 Transformable airship

[0199] PTL7: US7997532B2 Airborne power station

[0200] PTL8: US20130126675A1 Durable airship hull and in situ airship hull repair

[0201] PTL9: US8800628B2 Self-propelled airship hull repair system

[0202] PTL10: US9246433B2 Airborne Photovoltaic Solar Device And Method

[0203] PTL11: US11459080B2 Transformable Stratospheric Airship

[0204] PTL12: WO2021068457A1 Stratospheric airship of large-scale rigid and flexible integrated structure

[0205] Non-patent literature

[0206] NPL1: Evolution of the Rigid Airship Design, Baron L. d'Orcy, Scientific American, Vol. 115, No. 26 (December 23, 1916), p. 576, 579, 581 (“Evolution of the Rigid Airship Design”, Baron L. d'Orcy, Scientific American, Vol. 115, No. 26 (December 23, 1916), pp. 576, 579, 581)

[0207] NPL2: Airships: A New Horizon for Science, Keck Institute for Space Studies, 2013 (“Airships: A New Horizon for Science”, Keck Institute for Space Studies, 2013)

[0208] NPL3: Weinan et al., "Anovel inflatable rings supported design and buoyancy-weight balance deformation analysis of stratosphere airships." Chinese Journal of Aeronautics, Volume 35, Issue 1, January 2022, Pages 340-347 (Weinan et al., "A novel inflatable rings supported design and buoyancy-weight balance deformation analysis of stratosphere airships", Journal of Aeronautics (English Edition), Volume 35, Issue 1, January 2022, Pages 340-347)

[0209] NPL4: Vallabh et al. "Ultra-lightweight fiber-reinforced envelope material for a high-altitude airship." The Journal of The Textile Institute (2021): 1-7.

[0210] NPL5: Papez et al, "Overview of the Current State of Gallium Arsenide-Based Solar Cells". Materials 2021, 14, 3075. (Papez et al., "Overview of the Current State of Gallium Arsenide-Based Solar Cells". Materials 2021, 14, 3075).

Claims

1. A variable volume aerostat capable of expanding its surface area, comprising: one or more flat gas containment members made of a lightweight material impermeable to the lifting gas; a depth constraining structure constraining the depth of the flat gas-enclosing member; an aerostat body, in the form of an airship or balloon, joined to the flat gas-enclosing member; an opening or tube member that enables lift gas to flow between a gas chamber within one or more of the aerostat bodies and an interior of the flat gas-enclosing member; wherein, in the stowed configuration, the flat gas-enclosing member is not inflated and the air chamber within the aerostat body contains substantially all of the lifting gas; and Wherein, in the deployed configuration, lifting gas fills the flat gas-enclosing member, the flat gas-enclosing member is fully extended and self-supporting, and presents a much larger area to the sun than that presented by the aerostat body.

2. A variable volume aerostat according to claim 1, which also includes a reinforcement member of the flat gas enclosure member, which, as an example but not limitation, can be composed of strong lightweight fibers woven into the material of the enclosure member or strong lightweight cable members attached to the enclosure member at intervals.

3. The variable volume aerostat of claim 1 further comprising a lightweight tube member along the width of the flat gas enclosure member, wherein: The flow of lifting gas between the flat gas-enclosing member and the gas chambers within one or more of the aerostat bodies is accelerated.

4. The variable volume aerostat according to claims 2 and 3, wherein: The tube member is made of a strong and lightweight material and provides the necessary lateral reinforcement to the flat gas enclosing member.

5. The variable volume aerostat according to claim 3, further comprising: The flat gas-enclosing member is divided into separate sections along its width; a series of active or passive valves in the tube member that control the flow of lift gas between the inner containment member and various sections of the flat gas containment member; wherein during ascent, lifting gas expanding from the inner enclosure members of one or more of the aerostat bodies is directed into the deploying or opening sections of the flat gas enclosure members; and Therein, during descent, lifting gas is directed out of the reeling or folding section of the flat gas-enclosing member into an air chamber within the aerostat body.

6. The variable volume aerostat of claim 1, further comprising: a cylindrical structure at one or either end of the flat gas enclosing member which is rotatable on a longitudinal axis and serves as a take-up roller; a non-rotating attachment point joined to an end of a longitudinal axis of the one or more take-up rollers via a rotating support member; wherein, before the invention is raised, the uninflated flat gas-enclosing member can be rolled up onto the one or more rolls; wherein, as the invention rises, the flat gas-enclosing member can be unwound from the one or more reel wheels and inflated with lifting gas; wherein as the invention is lowered, the deflated flat gas-enclosing member can be reeled back onto the one or more reeling rollers; and Therein, any tethering member, propulsion system, additional buoyancy or other non-rotating structure can be attached to the wind-up roller at a non-rotating external attachment point on the longitudinal axis.

7. The variable volume aerostat according to claims 6 and 2, wherein The cable member has a diamond-shaped cross-section of constant size; The cable member is integrated into the top and bottom surfaces of the flat gas-enclosing member; The cable member is offset from the bottom cable member by half of its width; For each circumference of the winding roller, the cable member diverges by an amount equal to one complete cable member width; wherein, in the reeled configuration, a lower inner facet of each subsequent layer of the cable member rests on an outer upper facet of a previous layer of the cable member; and Therein, the cable member forms a natural guide for successful and compact reeling of the flat gas-enclosing member.

8. The variable volume aerostat according to claims 6 and 3, wherein The tube member has a diamond-shaped cross section with constant size; The tube member is integrated into the top and bottom surfaces of the flat gas enclosing member; The top tube member is offset from the bottom tube member by half its width; For each circumference of the winding roller, the tubular member is diverged by an amount equal to a complete cable member or tubular member width; wherein, in the coiled configuration, a lower inner facet of each subsequent layer of the tubular member rests on an outer upper facet of a previous layer of the tubular member; and Therein, the tube member forms a natural guide for successful and compact rolling up of the flat gas enclosing member.

9. The variable volume aerostat according to claim 6, further comprising: matching holes in opposing surfaces of the tube member; a sealing coating on said opposing surfaces of said tube member; and Therein, the holes act as passive valves by sealing against the movement of lift gas when pressed together.

10. The variable volume aerostat of claim 6, forming a retractable aerostat, wherein: The one or more reel-ups are also the aerostat body, formed by a rotatable airship having a main body in the shape of a generally cylindrical body; In the stowed configuration, the flat gas-enclosing member is not inflated and is rolled around the rotatable one or more airships; As the invention ascends, the flat gas-enclosing member is deployed by controlled rotation of the rotatable airship and inflated with lifting gas expanding from a gas chamber within the rotatable airship; In the deployed configuration, the flat gas-enclosing member is fully deployed and filled with sufficient lifting gas to provide it with balanced buoyancy; and As the invention descends, the flat gas-enclosing member reels around the body of the rotatable airship during a controlled rotation, pushing the lifting gas back into the air chamber within the rotatable airship.

11. The retractable aerostat according to claim 10, further comprising: an external swivel device suspended below the external attachment point; an energy storage device or other mass member mounted on said external rotating device at a significant distance from the longitudinal axis of said rotatable airship; a motor, gears and control mechanism attached to the rotating support member; as well as Onboard control systems; wherein the off-axis weight of the external rotating device provides a restoring torque; and wherein the off-axis buoyancy of any additional buoyancy provides a restoring torque; and The rotatable airship is rotated by torque applied by each rotating support member.

12. The retractable aerostat according to claim 10, further comprising: one or more internal rotating devices suspended within the interior of the rotatable airship along the longitudinal axis via a rotating support member; an energy storage device or other mass member mounted on said internal rotating device at a significant distance from the longitudinal axis of the rotatable airship; a motor, gears, and control mechanisms attached to each rotating support member; wherein the torque applied by each rotating support member causes the rotatable airship to rotate in response to the restoring torque provided by the off-axis weight; and wherein the combined weight of the inner rotating device and the outer rotating device is more evenly distributed along the length of the rotatable airship; and Therein, the rotatable airship can rotate without having to overcome a deflection along its longitudinal axis caused by an uneven weight distribution.

13. The retractable aerostat of claim 10, further comprising a rack and pinion swivel system comprising: One or more annular tracks, which are composed of racks and parallel guides, are installed around the inner circumference or outer circumference of the rotatable airship; a rail car, which carries a heavy counterweight, such as a battery, that can be driven along the rack by rotating a pinion; A power rail or spark-safe electrical connection point to allow the autonomous vehicle to exchange power with the main electrical system; in, The railcar applies a torque about the longitudinal axis of the rotatable airship proportional to the sine of the angle between its position and vertical; and wherein the off-axis weight used to rotate the rotatable airship is more evenly distributed along the length of the rotatable airship; and Therein, the rotatable airship can rotate without having to overcome a deflection along its longitudinal axis caused by an uneven weight distribution.

14. The retractable aerostat according to claim 13, further comprising: a longitudinal rack track that intersects the annular track around a circumference; A rotation intersection point between the circular track and the straight track; wherein the track vehicle is capable of longitudinal movement between different circular tracks; and The center of mass of the rotatable airship can be moved forward or backward for the purpose of controlling its pitch.

15. The variable volume aerostat of claim 6, further comprising A structure for suspending the winding roller below the aerostat body; a rotary joint, which by way of example and not limitation can consist of a rotary joint, connecting the tubular member from the aerostat body to the flat gas-enclosing member at the axis of the take-up roller; a motor and control system for rotating the take-up roller; wherein the flat gas enclosing member can be unfolded or rolled up by rotating the one or more winding rollers; and Wherein, the lifting gas can move between the air chamber in the aerostat body and the flat gas-enclosing member.

16. The variable volume aerostat of claim 1, further comprising a multi-directional propulsion system comprising a thruster attached to the aerostat body, an energy storage device, and a control system, wherein: The relative position of the aerostat body can be precisely controlled; The invention is capable of changing its orientation, position and speed; and By separating the aerostat bodies using the multi-directional propulsion system, lateral tensile forces can be applied along the width of the flat gas-enclosing member.

17. The variable volume aerostat of claim 1, further comprising one or more lightweight tether members attaching the invention to a winch member at the surface of the earth or mounted on a vehicle at a lower altitude, wherein: The invention is able to rise to great heights while its geographical position is controlled by the forces applied through the tether members.

18. The variable volume aerostat of claim 6, further comprising a lightweight tether member attached to the non-rotating external attachment point and to winch members spaced apart by more than the full width of the flat gas enclosure member, and a motor and control system to control the rotation of the wind-up roller, wherein: In the stowed configuration, the tether member is retracted, a majority of the flat gas-enclosing member is reeled in, and rotation of the reel roller is locked; During deployment, the tether members smoothly unwind, allowing the invention to ascend; As the invention rises, the force applied by the tether member is allowed to smoothly rotate the take-up roller while maintaining a certain tension in the flat gas enclosure member, unrolling the flat gas enclosure member, which is filled with lifting gas; and In the deployed configuration, the force exerted by the tether member continues to maintain the position of the invention and the tension in the flat gas-enclosing member.

19. The variable volume aerostat according to claim 6, further comprising two drum members at either end of each of the winding rollers, and a pair of tether members wound in opposite directions around the two drum members, wherein: Different tensions applied to the tether member can be used to rotate the reel roller in order to unwind or rewind the flat gas enclosing member.

20. The variable volume aerostat of claim 1, further comprising folding points designed using, by way of example and not limitation, differential length or differential elasticity in the depth restraining structure, wherein: The flat gas enclosure member has a natural tendency to collapse due to differential buoyancy between the deepest and shallowest parts of the enclosure member; relaxation of the tensile tension applied at the aerostat body causes the flat gas-enclosing member to collapse; and The width and surface area of ​​the enclosing member can be reduced during hours of darkness.

21. The variable volume aerostat of claim 1, further comprising an additional central airship attached near a middle portion of the flat gas-enclosing member, wherein: The additional weight near the middle of the flat gas-enclosing member can be supported by the buoyancy of the central airship; The central airship can be used as an attachment point for a tether or cable member that connects the invention to the ground or to a low-altitude aircraft; and If the central airship is of the non-rigid type, it can act as a physical buffer between two of the aerostat bodies at the ends of the flat gas-enclosing member.

22. A variable volume aerostat according to claim 21, further comprising a variable buoyancy system in the central airship, such as a "secondary airbag" (PTL5), wherein: The variation in the buoyancy of the central airship can be used to help cause the flat gas-enclosing members to form a v-shape wherein the radiation active surface area is significantly reduced.

23. The variable volume aerostat of claim 1, wherein: The flat gas enclosing member has a high albedo top layer or coating wherein a high proportion of incident solar radiation is reflected back into space wherein during the day there is a web that cools the area on the earth's surface that is shaded by the invention.

24. The variable volume aerostat of claim 1, wherein: In the deployed configuration, the flat gas-enclosing member can be disconnected from the aerostat body to float freely in the atmosphere.

25. The variable volume aerostat for solar power generation according to claim 1, further comprising: an ultra-thin photovoltaic film layer on a top surface of the flat gas-enclosing member; Connecting conductors; Electrical control systems; as well as Electricity storage and / or transmission systems; During the day, a large amount of incoming solar radiation is converted into electricity.

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