恒温恒湿空调系统的优化控制与性能模拟

针对传统恒温恒湿空调系统表冷器采用固定露点方法导致热湿补偿损失较大的缺点,采用热湿独立控制装置和PID分程控制方法,研制了一套恒温恒湿空调系统。在实验的基础上,利用TRNSYS 16软件建模,对系统在不同热湿负荷下的运行状况及节能效果进行了模拟分析。结果表明,该系统能自动调节表冷器冷冻水流量与温度,以及加热器或加湿器的投入量,实现对空气温湿度的独立控制,并达到设定的温湿度;在设计此类表冷器时,换热面积应该以较高的冷冻水进口温度(如12℃而不是通常的7℃)来进行计算。该系统节能效果显著,比传统系统在低温高湿工况下节能30%以上;在高温低湿工况下节能50%左右。

Optimum Control Strategy and Performance Simulation of a Constant Temperature and Humidity Air-conditioning System

Due to the large energy compensation caused by the fixed dew point on the cooling coil(CC) in the conventional constant temperature and humidity air-conditioning system,a new system employing a temperature and humidity independent control device(THIC device) in the CC and a method of PID split-range control,is developed in this paper.Based on the experiment verification,the operation states and the energy saving effects of the system under different heat and moisture loads have been simulated by TRNSYS 16 software.The results show that under different working conditions,the system can automatically control air temperature and humidity independently with a high precision,by adjusting the mass flow rate and the temperature of the chilled water into the CC,and the output of the heater or the humidifier.In the design of such CC,the heat transfer area should be calculated under a higher inlet temperature of the chilled water(for example,12℃ instead of the usual 7℃).The system is energy-efficient with a rate of 30% under low temperature high humidity condition and about 50% under high temperature and low humidity condition,compared with the conventional system.