Circulatory system and aerostat for near space environment

Abstract

The present application belongs to the technical field of low-temperature heat exchange, and particularly relates to a circulating system for a near-space environment and a float vehicle. The circulating system comprises an air intake circulating module, a phase-change heat exchange module, a refrigeration and heating circulating module, and a flow control module. The present application realizes sufficient contact between the phase-change working medium and the phase-change heat exchange module through the air intake circulating module. The phase-change working medium realizes the liquefaction and vaporization process through the phase-change heat exchange module, and the flow distribution of the refrigerant in the first heat exchanger and the second heat exchanger is realized through the flow control module. In the refrigeration mode, more flow of the refrigerant is ensured to flow through the first heat exchanger, and in the heating mode, more flow of the refrigerant is ensured to flow through the second heat exchanger. The quick switching between the refrigeration mode and the heating mode is realized through the working medium circulating module, so as to realize the quick liquefaction and vaporization process of the phase-change working medium. Finally, the buoyancy and the height are adjusted through the large volume change of the phase-change working medium, and the long-term stable flight of the stratosphere float vehicle is realized.

Description

Technical Field

[0001] This invention belongs to the field of cryogenic heat exchange technology, and particularly relates to a circulation system and airship for near-space environments. Background Technology

[0002] Near space refers to the airspace 20–100 km above the ground, which has attracted widespread international attention due to its significant development and application value. Airships can fly stably for extended periods in this space, possessing advantages that aviation and aerospace airships lack, particularly in communication support, intelligence gathering, electronic jamming, early warning, and civilian applications, where they hold great potential. Achieving long-duration, stable operation of airships in the near-space environment is a global challenge. The greatest advantage of airships lies in their potential for long-term ambush; however, to date, no technology has truly achieved long-term, stationary operation of stratospheric airships. The "overheating" and "overpressure" phenomena caused by diurnal temperature variations are the primary obstacles to long-term ambush operation. During the day, the combined effects of direct solar radiation, ground albedo, and infrared radiation from the ground atmosphere can cause the internal gas temperature of the airship to be significantly higher than the external atmospheric temperature. Without venting, the pressure difference between the inside and outside may exceed the stress tolerance of the skin, reducing its service life. At night, the temperature and pressure of the gas inside the airship decrease as the air temperature drops. In order to maintain the pressure, air needs to be introduced, which will increase the weight of the airship and reduce the net buoyancy, thus affecting altitude maintenance.

[0003] Existing buoyancy control methods have fundamental flaws, making it inherently difficult to maintain a stationary position for extended periods. Currently, airships primarily control their buoyancy through primitive methods such as appropriate overpressure, deflation, and dropping weights. These methods not only fail to independently and effectively control the airship's altitude, pressure, and buoyancy but also have a significant negative impact on the airship's ability to maintain a stationary position for extended periods and on its effective payload. Summary of the Invention

[0004] This invention provides a circulation system and airship for near-space environments, which solves the shortcomings of existing technologies that cannot independently and effectively control the height, pressure and buoyancy of airships. It achieves active buoyancy regulation, does not exchange mass with the outside world, and realizes the phase change process of the internal working fluid continuously and reversibly through a thermodynamic circulation device, thereby controllably achieving constant total buoyancy.

[0005] This invention provides a circulation system and an airship for near-space environments, comprising: An air intake circulation module, comprising a phase change airbag and a circulating fan, wherein the phase change airbag is used to provide a phase change working fluid, and the air inlet of the circulating fan is connected to the phase change airbag; A phase change heat exchange module includes a liquefaction chamber, a first heat exchanger, a liquid collection chamber, and a second heat exchanger. The liquefaction chamber is connected to the air outlet of the circulating fan and the phase change airbag. The first heat exchanger is disposed in the liquefaction chamber, and the second heat exchanger is disposed in the liquid collection chamber. The liquefaction chamber and the liquid collection chamber are connected, and the first heat exchanger and the second heat exchanger are connected in parallel. The refrigerant circulation module includes a compressor unit, an air cooler, and a throttling element. In cooling mode, the high-pressure outlet of the compressor unit is connected to the high-pressure inlet of the air cooler; the high-pressure outlet of the first heat exchanger is connected to the high-pressure inlet of the air cooler; the high-pressure outlet of the air cooler is connected to the high-pressure inlet of the throttling element, and the low-pressure outlet of the throttling element is connected to the inlets of the first and second heat exchangers. In heating mode, the high-pressure outlet of the compressor unit is connected to the inlets of the first and second heat exchangers; the refrigerant outlets of the first and second heat exchangers are connected to the inlet of the throttling element, and the outlet of the throttling element flows back to the compressor unit through the air cooler. The flow control module is used to control the flow distribution of refrigerant in the first heat exchanger and the second heat exchanger.

[0006] According to the present invention, a circulation system for near-space environment further includes a control module for controlling the working fluid circulation module and the flow control module, so that the working fluid circulation module can switch between cooling mode and heating mode at any time while it is working.

[0007] According to the present invention, a circulation system for near-space environment is provided, wherein the flow control module includes a first solenoid valve, a first end of the first solenoid valve being connected to the throttling element, a second end of the first solenoid valve being connected to the first heat exchanger, and a third end of the first solenoid valve being connected to the second heat exchanger.

[0008] According to the present invention, a circulation system for near-space environment is provided, wherein the flow control module further includes a second solenoid valve, a first end of the second solenoid valve being connected to the compressor unit, a second end of the second solenoid valve being connected to the first heat exchanger, and a third end of the second solenoid valve being connected to the second heat exchanger.

[0009] According to the present invention, a circulation system for near-space environment is provided, wherein the flow control module further includes a four-way solenoid valve, the first end of the four-way solenoid valve being connected to the first end of the second solenoid valve, the second end of the four-way solenoid valve being connected to the low-pressure inlet of the compressor unit, the third end of the four-way solenoid valve being connected to the high-pressure outlet of the compressor unit, and the fourth end of the four-way solenoid valve being connected to the air cooler.

[0010] According to a circulation system for near-space environments provided by the present invention, the phase change heat transfer module further includes a level gauge, which is connected to the liquid collection chamber.

[0011] According to a circulation system for near-space environments provided by the present invention, the working fluid circulation module further includes a gas storage tank, which is disposed upstream of the inlet of the compressor unit.

[0012] According to the present invention, a circulation system for near-space environment is provided, wherein the first heat exchanger and the second heat exchanger include one of the following: shell and tube heat exchanger, jacketed heat exchanger, plate heat exchanger, plate-fin heat exchanger, and spiral plate heat exchanger.

[0013] According to the present invention, a circulating system for near-space environments is provided, wherein the refrigerant includes one of ethane and ethylene.

[0014] The present invention also provides an airship including a circulation system for near-space environments as described in any of the preceding claims.

[0015] The circulation system for near-space environments provided by this invention provides a phase change working fluid through a phase change airbag. The phase change working fluid enters the liquefaction chamber from the phase change airbag via a circulation fan. The working fluid that has not been completely liquefied returns to the phase change airbag through a pipeline, forming a complete loop. The phase change working fluid and the phase change heat exchange module are fully contacted through the air intake circulation module.

[0016] The liquefaction and vaporization of the phase change working fluid are achieved through a phase change heat exchange module. In cooling mode, the flow control module ensures a larger flow of refrigerant through the first heat exchanger, providing sufficient cooling for heat exchange with the gaseous phase change working fluid, allowing for rapid liquefaction. A smaller amount of refrigerant flows through the second heat exchanger, acting as subcooler to prevent the liquefied working fluid from returning to the phase change gas chamber. In heating mode, the flow control module ensures a larger flow of refrigerant through the second heat exchanger, providing sufficient heat for heat exchange with the liquid phase change working fluid, allowing for rapid vaporization. A smaller amount of refrigerant flows through the first heat exchanger, acting as superheater to prevent the liquefied working fluid from returning to the collection chamber.

[0017] The working fluid circulation module enables rapid switching between cooling and heating modes, thereby achieving rapid liquefaction and vaporization of the phase change working fluid.

[0018] The airship provided by this invention includes a circulation system for rapid liquefaction and vaporization in the near-space environment, as described above. It regulates buoyancy and altitude through large-volume changes of the phase-change working fluid, enabling long-term stable flight of the stratospheric airship. By controlling the flow distribution, rapid liquefaction and vaporization of the phase-change working fluid in the near-space environment can be achieved. The airship is compact, lightweight, simple in process, and highly energy-efficient. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a flowchart illustrating the refrigeration mode of the rapid liquefaction and vaporization circulation system for near-space environments provided by the present invention.

[0021] Figure 2 This is a flowchart illustrating the heating mode of the rapid liquefaction and vaporization circulation system for near-space environments provided by the present invention.

[0022] Figure label: 1. Phase change airbag; 2. Circulating fan; 3. Liquefaction chamber; 4. First heat exchanger; 5. Liquid collection chamber; 6. Second heat exchanger; 7. Compressor unit; 8. Air cooler; 9. Throttling element; 10. First solenoid valve; 11. Second solenoid valve; 12. Four-way solenoid valve; 13. Liquid level gauge; 14. Gas storage tank. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0024] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] The following is combined Figures 1-2 The present invention describes a circulation system for near-space environments.

[0026] The present invention provides a circulation system for near-space environments, comprising an air intake circulation module, a phase change heat transfer module, a cooling and heating circulation module, and a flow control module.

[0027] The air intake circulation module includes a phase change airbag 1, a circulation fan 2, and connecting pipes. The phase change airbag 1 is used to provide the phase change working fluid, and the air inlet of the circulation fan 2 is connected to the phase change airbag 1. The phase change working fluid enters the liquefaction chamber 3 from the phase change airbag 1 through the circulation fan 2. The working fluid that has not been liquefied returns to the phase change airbag 1 through the pipes, forming a complete loop.

[0028] The phase change heat exchange module includes a liquefaction chamber 3, a first heat exchanger 4, a liquid collection chamber 5, a second heat exchanger 6, and connecting pipes. The air outlet of the circulating fan 2 and the liquefaction chamber 3 are both connected to the phase change air bag 1. The first heat exchanger 4 is located in the liquefaction chamber 3, and the second heat exchanger 6 is located in the liquid collection chamber 5. The liquefaction chamber 3 and the liquid collection chamber 5 are connected, and the first heat exchanger 4 and the second heat exchanger 6 are connected in parallel.

[0029] In cooling mode, the phase change working fluid enters the liquefaction chamber 3 through the circulating fan 2 and exchanges heat with the first heat exchanger 4. The cooled phase change working fluid will condense and enter the liquefaction chamber 3. At the same time, it exchanges heat with the second heat exchanger 6 to achieve recooling and prevent the phase change working fluid from vaporizing back to the phase change gas bag 1. The liquid phase change working fluid drips into the liquid collection chamber 5.

[0030] In heating mode, the liquid phase change working fluid exchanges heat with the second heat exchanger 6 and is vaporized by heat, becoming a gaseous phase change working fluid with a lower density. It leaves the liquid collection chamber 5 and enters the liquefaction chamber 3, where it continues to exchange heat with the first heat exchanger 4 to achieve superheating. Finally, it returns to the phase change gas bag 1 through the pipeline.

[0031] The working fluid circulation module includes a compressor unit 7, an air cooler 8, and a throttling element 9.

[0032] In cooling mode, the high-pressure refrigerant outlet of compressor unit 7 is connected to the high-pressure inlet of air cooler 8; the high-pressure refrigerant outlet of first heat exchanger 4 is connected to the high-pressure inlet of air cooler 8; the high-pressure refrigerant outlet of air cooler 8 is connected to the high-pressure refrigerant inlet of throttling element 9, and the low-pressure refrigerant outlet of throttling element 9 is connected to the refrigerant inlets of first heat exchanger 4 and second heat exchanger 6. The low-pressure refrigerant outlets of first heat exchanger 4 and second heat exchanger 6 are connected to the low-pressure refrigerant inlet of compressor unit 7, forming a complete circuit: A→B(C)→E(D)→F→G→H→I→J→A.

[0033] In heating mode, the high-pressure refrigerant outlet of compressor unit 7 is connected to the refrigerant inlet of the first heat exchanger 4 and the second heat exchanger 6. In heating mode, the first heat exchanger 4 and the second heat exchanger 6 cool the refrigerant. The refrigerant outlet of the first heat exchanger 4 and the second heat exchanger 6 is connected to the inlet of the throttling element 9. After passing through the outlet of the throttling element 9, the refrigerant passes through the air cooler 8. In heating mode, the air cooler 8 heats the refrigerant. After passing through the air cooler 8, the refrigerant flows back to the low-pressure inlet of compressor unit 7 and forms a complete circuit: A→J→I→G→H→F→E(D)→B(C)→A.

[0034] The flow control module is used to control the flow distribution of refrigerant in the first heat exchanger 4 and the second heat exchanger 6. Under the operation of the working fluid circulation module, it can switch between cooling and heating modes at any time and distribute the flow reasonably to realize the rapid liquefaction and vaporization processes of the phase change working fluid in the near-space environment.

[0035] In one feasible embodiment of the present invention, a control module is further included to control the working fluid circulation module and the flow control module, so that the working fluid circulation module can switch between cooling mode and heating mode at any time while it is working.

[0036] In a feasible embodiment of the present invention, the flow control module includes a first solenoid valve 10, which is key to achieving rapid liquefaction of the phase change working fluid in the near-space environment. Its connection method is as follows: the first end of the first solenoid valve 10 is connected to the throttling element 9, the second end of the first solenoid valve 10 is connected to the first heat exchanger 4, and the third end of the first solenoid valve 10 is connected to the second heat exchanger 6.

[0037] The rapid liquefaction process is as follows: the refrigerant flows through the outlet of the throttling element 9, through pipe A into the first solenoid valve 10, and then through the first solenoid valve 10 it is divided into two paths: one flows through pipe B to the first heat exchanger 4, and the other flows through pipe C to the second heat exchanger 6. In the cooling mode, the flow distribution of the refrigerant in the first heat exchanger 4 and the second heat exchanger 6 can be controlled by the first solenoid valve 10, so that the flow rate in the first heat exchanger 4 is larger to achieve rapid liquefaction, and the flow rate of the refrigerant in the second heat exchanger 6 is smaller to achieve the recooling function and prevent the liquid phase change working fluid from revaporizing.

[0038] In a feasible embodiment of the present invention, the flow control module further includes a second solenoid valve 11, which is the key to realizing the rapid vaporization of the phase change working fluid in the near-space environment. The connection method is that the first end of the second solenoid valve 11 is connected to the compressor unit 7, the second end of the second solenoid valve 11 is connected to the first heat exchanger 4, and the third end of the second solenoid valve 11 is connected to the second heat exchanger 6.

[0039] The rapid vaporization process is as follows: after passing through the compressor unit 7, the refrigerant flows through pipeline E to the first heat exchanger 4, and through pipeline D to the second heat exchanger 6. In heating mode, the flow distribution of the refrigerant in the first heat exchanger 4 and the second heat exchanger 6 can be controlled by the second solenoid valve 11, so that the flow rate in the second heat exchanger 6 is larger, achieving rapid vaporization, while the flow rate of the refrigerant in the first heat exchanger 4 is smaller, achieving the superheating function and preventing the gaseous phase change working fluid from reliquefying.

[0040] In a feasible embodiment of the present invention, the flow control module further includes a four-way solenoid valve 12, which is key to realizing the liquefaction and vaporization of the phase change working fluid. The first end of the four-way solenoid valve 12 is connected to the first end of the second solenoid valve 11, the second end of the four-way solenoid valve 12 is connected to the low-pressure inlet of the compressor unit 7, the third end of the four-way solenoid valve 12 is connected to the high-pressure outlet of the compressor unit 7, and the fourth end of the four-way solenoid valve 12 is connected to the air cooler 8.

[0041] In cooling mode, the refrigerant passes through the first heat exchanger 4, the second heat exchanger 6, and the second solenoid valve 11, then through the four-way solenoid valve 12 via pipeline F, and then through the compressor unit 7 via pipeline G. After passing through the compressor unit 7, the refrigerant flows into the four-way solenoid valve 12 via pipeline H, and finally through the four-way solenoid valve 12, and then through pipeline I into the air cooler 8.

[0042] In heating mode, the refrigerant flows out from the air cooler 8, flows into the four-way solenoid valve 12 through pipe I, then through pipe G through the compressor unit 7, and after passing through the compressor unit 7, the refrigerant flows into the four-way solenoid valve 12 through pipe H, and finally flows into the first heat exchanger 4 and the second heat exchanger 6 through pipe F through the second solenoid valve 11.

[0043] In a feasible embodiment of the present invention, the phase change heat transfer module further includes a level gauge 13, which is connected to the liquid collection chamber 5 and is used to measure the liquefaction rate of the liquid collection chamber 5 in real time.

[0044] In a feasible embodiment of the present invention, since the near-space environment is a low-temperature and low-pressure condition, a low-temperature refrigerant is required to achieve rapid liquefaction and vaporization of the phase change working fluid. The low-temperature refrigerant can be one of ethane or ethylene.

[0045] In a feasible embodiment of the present invention, the first heat exchanger 4 and the second heat exchanger 6 include one of the following: shell and tube heat exchanger, jacketed heat exchanger, plate heat exchanger, plate-fin heat exchanger, and spiral plate heat exchanger.

[0046] In a feasible embodiment of the present invention, in order to prevent overpressure when charging refrigerant into the refrigeration system under normal pressure, the working fluid circulation module further includes a gas storage tank 14, which is located upstream of the inlet of the compressor unit 7 to store refrigerant and prevent system overpressure.

[0047] Therefore, the circulation system for near-space environments provided by this invention can quickly switch between wet cooling and heating modes through the working fluid circulation module, thereby realizing the rapid liquefaction and vaporization of the phase change working fluid. Ultimately, the buoyancy and altitude are controlled by the large volume change of the phase change working fluid, enabling the long-term stable flight of the stratospheric airship. The circulation system can realize the rapid liquefaction and vaporization of the phase change working fluid in the near-space environment through flow distribution. It has a compact structure, small mass, simple process, and high efficiency and energy saving.

[0048] The airship provided by the present invention will be described below. The airship described below can be referred to in correspondence with the circulation system for near-space environment described above.

[0049] A second aspect of the present invention provides an airship comprising a circulation system for near-space environments as described in any of the preceding claims.

[0050] The airship provided by the second aspect of the present invention, having included a circulation system for rapid liquefaction and vaporization in the near-space environment as described above, can regulate buoyancy and altitude through large-volume changes in the phase change working fluid, thereby enabling long-term stable flight of the stratospheric airship.

[0051] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0052] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "method," "specific method," or "some methods," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or method is included in at least one embodiment or method of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or method. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or methods. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or methods described in this specification, as well as the features of different embodiments or methods.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A circulation system for near-space environments, characterized in that, include: An air intake circulation module, comprising a phase change airbag (1) and a circulating fan (2), wherein the phase change airbag (1) is used to provide a phase change working fluid, and the air inlet of the circulating fan (2) is connected to the phase change airbag (1); The phase change heat exchange module includes a liquefaction chamber (3), a first heat exchanger (4), a liquid collection chamber (5), and a second heat exchanger (6). The air outlet of the circulating fan (2) and the phase change air bag (1) are both connected to the liquefaction chamber (3). The first heat exchanger (4) is located in the liquefaction chamber (3), and the second heat exchanger (6) is located in the liquid collection chamber (5). The liquefaction chamber (3) and the liquid collection chamber (5) are connected, and the first heat exchanger (4) and the second heat exchanger (6) are connected in parallel. The refrigerant circulation module includes a compressor unit (7), an air cooler (8), and a throttling element (9). In cooling mode, the high-pressure outlet of the compressor unit (7) is connected to the high-pressure inlet of the air cooler (8); the high-pressure outlets of the first heat exchanger (4) and the second heat exchanger (6) are connected to the high-pressure inlet of the air cooler (8); the high-pressure outlet of the air cooler (8) is connected to the high-pressure inlet of the throttling element (9), and the low-pressure outlet of the throttling element (9) is connected to the inlets of the first heat exchanger (4) and the second heat exchanger (6); in heating mode, the high-pressure outlet of the compressor unit (7) is connected to the inlets of the first heat exchanger (4) and the second heat exchanger (6); the refrigerant outlets of the first heat exchanger (4) and the second heat exchanger (6) are connected to the inlet of the throttling element (9), and the outlet of the throttling element (9) flows back to the compressor unit (7) through the air cooler (8). The flow control module is used to control the flow distribution of refrigerant in the first heat exchanger (4) and the second heat exchanger (6).

2. The circulation system for near-space environments according to claim 1, characterized in that, It also includes a control module for controlling the working fluid circulation module and the flow control module, so that the working fluid circulation module can switch between cooling mode and heating mode at any time.

3. The circulation system for near-space environments according to claim 2, characterized in that, The flow control module includes a first solenoid valve (10), the first end of which is connected to the throttling element (9), the second end of which is connected to the first heat exchanger (4), and the third end of which is connected to the second heat exchanger (6).

4. The circulation system for near-space environments according to claim 2, characterized in that, The flow control module also includes a second solenoid valve (11), the first end of which is connected to the compressor unit (7), the second end of which is connected to the first heat exchanger (4), and the third end of which is connected to the second heat exchanger (6).

5. The circulation system for near-space environments according to claim 4, characterized in that, The flow control module also includes a four-way solenoid valve (12), the first end of which is connected to the first end of the second solenoid valve (11), the second end of which is connected to the low-pressure inlet of the compressor unit (7), the third end of which is connected to the high-pressure outlet of the compressor unit (7), and the fourth end of which is connected to the air cooler (8).

6. The circulation system for near-space environments according to claim 1, characterized in that, The phase change heat transfer module also includes a level gauge (13), which is connected to the liquid collection chamber (5).

7. The circulation system for near-space environments according to claim 1, characterized in that, The working fluid circulation module also includes a gas storage tank (14), which is located upstream of the inlet of the compressor unit (7).

8. The circulation system for near-space environments according to claim 1, characterized in that, The first heat exchanger (4) and the second heat exchanger (6) include one of the following: shell and tube heat exchanger, jacketed heat exchanger, and plate heat exchanger. The plate heat exchanger includes plate-fin heat exchanger and spiral plate heat exchanger.

9. The circulation system for near-space environments according to claim 1, characterized in that, The refrigerant includes one of ethane and ethylene.

10. An airship, characterized in that, Includes a circulation system for near-space environments as described in any one of claims 1 to 9.

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