二次回风在小型恒温恒湿空调系统中应用的实验研究
Experimental study on application of secondary return air to small constant temperature and humidity systems
摘要：
构建了一个小型恒温恒湿实验室，在夏季工况下，采用定露点控制，运用静态调节法，调节二次回风系统的混合比，并进行了系统的节能效果、控制精度、抗干扰能力测试。测试结果表明：二次回风系统与一次回风系统相比，可有效减少再热量；随着二次回风量的增加，再热量逐步减小，当二次回风调节阀开大至50%时，再热量可减至31%；系统运行稳定，温度波动范围±0.3 ℃，相对湿度波动范围±2%。对于二次回风系统，在固定混合比的前提下，室内扰动比室外扰动对室内温湿度控制波动影响大。系统不仅可以有效减少再热量，而且具有较好的抗干扰性和较高的控制精度。
Abstract：
Constructs a small constant temperature and humidity system and tests the energy saving effect, control precision and anti-disturbance ability with fixed dew point control and static adjustment method by adjusting the mixing ratio of secondary return air to primary return air under the summer working condition. The results show that the secondary return air system can effectively reduce the reheating capacity compared with the primary return air system. With the increase of the secondary return air rate, the heating capacity gradually decreases, and when the regulating valve of the secondary return air opens to 50%, the heating capacity reduces to 31%. The system operates stably, and the temperature fluctuation range is ±0.3 ℃, and the relative humidity fluctuation range is ±2%. For the secondary return air system under the fixed mixing ratio, the indoor disturbance has a greater effect on the indoor temperature and humidity control fluctuation than the outdoor disturbance. This system not only can effectively reduce the reheating capacity, but also has good anti-disturbance ability and high control accuracy.
Keywords:constant temperature and humidity, air conditioning, static regulation, secondary return air, mixing ratio, energy saving, disturbance