一种低温溶液除湿自主再生热泵空调系统的基础研究

This project puts forward a novel temperature and humidity independent control air-conditioning system, which is a combination of vapor compression refrigeration and liquid desiccant dehumidification system. The main working principle of this system is that, the cooling capacity from an evaporator is used to control the temperature of liquid desiccant and process air while the heat rejected from the condenser is used to regenerate liquid desiccant. The sensible and latent cooling load of fresh air is handled effectively by the novel system with proper liquid desiccant condition chosen. As unconventional-temperature solution is used during the dehumidification process, compared with the conventional liquid desiccant air-conditioning system the liquid desiccant mass fraction of this system can reduce about 15%.This would lead to smaller demand of regenerative heat. The condensing heat of vapor compression refrigeration system is treated by both air condensation and solution condensation, which can avoid equipment corrosion and demonstrate effectively use of the condensation heat. Over most of the conditions the amount of heat from the condenser is enough for liquid desiccant regeneration. Compared with the traditional dew point control air conditioning system or conventional liquid desiccant dehumidification system, the energy saving characteristics of this new system is significant. We will carry out both theoretical analysis and experimental research during the project progress and the main contents of this project research are as follows: the study of heat and mass transfer characteristics of unconventional-temperature liquid desiccant dehumidification process; the effective way to use heat rejected from the condenser to regenerate the liquid desiccant to improve the performance of system and conserve energy; the development of system prototype; the construct of a comprehensive test platform; the experimental and simulation analysis of system performance; the find of optimal operation parameters range of the system; the optimization of system structure and control operation strategy, and so on.

本项目提出一种将蒸汽压缩式制冷与溶液除湿技术相结合的新型空调系统，利用低温除湿溶液处理环境空气。该系统空气处理方式兼具热湿耦合处理与温湿度独立控制的特性，空气经除湿器除湿、降温后再由干式表冷器对温度进行精确控制。除湿溶液相对常规溶液除湿空调系统其浓度可降低15%左右，再生热量需求小。蒸汽压缩式循环的冷凝热在全工况条件下均能够满足溶液再生需求，且冷凝热处理采用空气冷凝与溶液冷凝相结合的方式、避免了溶液对设备腐蚀的同时有效利用了冷凝热。相比传统露点控制空调系统或常规溶液除湿空调系统，该系统的节能效果明显。采用理论与实验相结合的方式，主要研究系统的耦合形式及热力学性能提升方法，研究完善溶液与制冷剂所涉及的热力过程，实现合理的冷凝热处理及溶液的高效再生；研制系统样机，实验测定和模拟分析系统性能，确定最优运行参数范围，优化系统结构及控制运行策略。项目研究的成果将为该新型空调系统的实际应用奠定基础。

为了解决现有常规空调系统、部分温湿度独立控制空调系统以及溶液除湿热泵系统中所存在的不足，本项目对现有的蒸汽压缩式制冷与溶液除湿技术相结合的复合型空调系统进行了改进，提出一种新型的能够实现自主再生的低温溶液除湿热泵空调系统。该系统空气处理方式兼具热湿耦合处理与温湿度独立控制的特性，空气经除湿器除湿、降温后再由干式表冷器对温度进行精确控制。该系统采用低温的除湿溶液，除湿溶液的温度由压缩制冷循环的蒸发器进行调节，所以除湿溶液可以在较低浓度下运行，相对常规溶液除湿空调系统其浓度可降低15%左右，除湿后稀溶液的再生难度降低，再生热量需求小；冷凝热的处理采用空气冷凝与溶液冷凝相结合的方式、减小了溶液对设备腐蚀的同时有效的利用了冷凝热，冷凝热在正常工况及极端工况下均能够完全满足溶液再生的需求，提高了溶液再生冷凝热利用率。相比传统露点控制空调系统或常规溶液除湿空调系统，该系统的节能效果明显。课题采用理论与实验相结合的方式，重点研究低温溶液除湿过程中的热质传递特性、合理的冷凝热处理方式、以及系统运行参数之间的匹配特性。同时进一步研究系统的耦合形式及热力学性能提升方法，研究完善溶液与制冷剂所涉及的热力过程，实现合理的冷凝热处理及溶液的高效再生；研制系统样机，实验测定和模拟分析系统性能，确定最优运行参数范围，优化系统结构及控制运行策略。项目研究的成果将为该新型空调系统的实际应用奠定了一定理论研究应用基础。