摘要平流层飞艇在工作时设备舱中的设备会产生大量的热量，若热量不能及时散走，将对设备的工作性能产生重大的影响，甚至导致设备损坏。为了保证设备能够正常工作，需要对设备舱舱体及舱内设备进行合理的热控制设计。本文在分析舱体及舱内设备传热机理的基础上 ，基于理论计算的方法，对平流层飞艇电子设备舱热设计系统中所涉及的关键问题进行了研究。87024

首先，对平流层飞艇上升过程的运动轨迹进行了研究。通过分析飞艇上升过程中的受力情况以及热传递情况，建立了飞艇的运动模型和传热模型，利用VC++软件编程求解，得到了飞艇上升过程中的运动轨迹曲线，并采用分段函数对其进行拟合，得到了飞艇上升高度随时间的变化关系。

其次，对电子设备舱进行了整体热设计研究。在分析平流层飞艇电子设备舱传热特性的基础上，提出了一种采用开放式送风的平流层飞艇电子设备舱整体环境控制方案。建立了电子设备舱的传热模型，对定风量和变风量两种情况下设备舱内温度的变化进行了理论计算。计算结果表明，采用变风量的设计方案效果要优于定风量的设计方案。

最后，对电子设备舱的局部热设计进行了研究。首先基于定风量和变风量两种模式对冷板的全高度性能进行了研究，研究结果表明，定风量时冷板的温度将降低至-10℃左右，将会影响电子设备的正常工作，因此本文推荐使用变风量的冷板冷却方案。其次，针对地面环境温度较高时飞艇起飞阶段电子设备散热系统无法起到冷却的效果以及在高空时风机进气流量受限的问题，本文提出了一种基于开放式二氧化碳制冷的电子设备冷却方案，并对其进行了相关的理论计算。计算结果表明，其能够解决上述方案存在的问题。同时，论文还从多个角度分析了二氧化碳制冷剂制冷量损失的影响因素，为二氧化碳开放式制冷系统的实际应用提供了有利的依据。

毕业论文关键词：平流层飞艇；电子设备舱；热控系统；二氧化碳制冷；变风量

Abstract When the stratospheric airship is working, the equipment can generate a lot of heat which influences the performance of the equipment significantly，or even causes damage to the equipment if the heat is not taken away in time。 In order to ensure that the equipment can work normally, reasonable thermal design is required for the electronic equipment cabin and the equipment itself。 Therefore, this paper has studied the relevant problems with the thermal design of the equipment cabin of the stratospheric airship by means of theoretic calculation。

Firstly, this paper analyzes the trajectory of the ascending process of a stratospheric airship。 By analyzing the force and the heat transfer during the ascending process, the motion model and heat transfer model of the airship are established,and the trajectory curve of the airship is obtained by programming with VC++ software。 In addition, the relationship between height and time is also obtained by the two fitting。

Secondly, this paper analyzes the overall thermal design of the electronic equipment cabin。 An integrated environment control scheme of the electronic equipment cabin is proposed on the basis of analyzing the heat transfer characteristics of the stratospheric airship。 Besides, this paper establishes the model of the electronic equipment cabin, and carries out the theoretical calculation of the change of the temperature in the condition of constant air volume and variable air volume 。 The result shows that the design scheme of variable air volume is better than that of constant air volume。

Finally, this paper analyzes the local thermal design of the electronic equipment cabin。 At first, this paper studies the full height performance of the cold plate in two cases of constant air volume and variable air volume。 The result show that the temperature of the cold plate with constant air volume is reduced to about -10℃, which does not conform to the design requirements。 Therefore, this paper recommends the scheme of variable volume。 Then, in view of the poor cooling effect when the temperature is too high, as well as the insufficient intake of air at high altitude, this paper proposes a cooling scheme based on the open-type refrigeration of carbon dioxide。 The calculation results show that the scheme can solve the problems mentioned above。 In this paper, the influence factors of carbon dioxide refrigerant cooling capacity loss are analyzed from several angels。 The results of this paper provide a technical reference for the practical application of the carbon dioxide refrigeration system。