人工环境库诱导式温湿调控系统设计探讨

针对人工环境库温湿调控的特殊要求，设计了空气诱导式湿度调节与空气干式集中升降温处理的诱导式温湿度调控系统；对四种方向的温湿度调控过程进行了理论分析及设计计算，进而设计了“先调温后调湿”的配套自动控制流程，并以试验实例结果进行了讨论。结果说明该系统可提高人工环境库温湿调控可靠性及控制品质。     

工程温湿度独立控制系统的应用

为了推广温湿度独立控制系统这一新型节能技术,介绍了潮湿地区(Ⅱ区)热泵驱动式溶液调湿机组的应用,对温湿度独立控制系统负荷计算、设备选型进行了详细的描述。温湿度独立控制系统相比常规空调系统节能30%且舒适性强。提出了溶液调湿机组在我国潮湿地区(Ⅱ区)有广泛的应用前景。并与传统空调系统相比较,论述了温湿度独立控制系统的优点及不足。     

温湿度独立控制空调系统的现状分析

介绍了温湿度独立控制空调系统的基本原理和相关设备,综述了该系统在节能方面的优势,并且与常规中央空调系统做了比较,通过总结该系统目前研究中存在的一些问题,对未来温湿度独立控制空调系统的发展提出了展望.     

基于ZigBee及PSO-BP神经网络的温室温湿度检测系统

为了满足日益发展的农业技术需求,并提高温室系统温湿度检测的精度,本文设计了基于PSO-BP神经网络的温室无线温湿度检测系统.该系统硬件结构由基于CC2530芯片制成的开发板及SHT11温湿度传感器实现,在采集数据的过程中加入经粒子群算法优化（PSO）的神经网络,以此补偿检测过程的非线性误差.通过Matlab软件仿真可验证PSO-BP神经网络的补偿效果.在实验环境下,此系统运行正常.     

Fuzzy logic based energy saving technique for a central air conditioning system

In this paper a scheme has been proposed to maintain the temperature and the humidity, in each of the rooms served by a central Air Conditioner (AC) unit, close to the targeted values, and reduce the electrical energy intake of the AC compressor. The upper limits of the comfort zone, typically marked at a temperature of 25 °C and a relative humidity of 70%, are used as the targets. It should be noted that a conventional AC system controls humidity in its own way without giving the users any scope for changing the set point for the targeted humidity unlike the scope it offers to change the set point for the targeted temperature through a thermostat. But in this work this limitation has been taken into cognizance and overcome to a great extent using fuzzy logic to represent the intricate influences of temperature on the humidity of the space being cooled and correct the thermostat setting. In the developed scheme, the sensor captured temperature and humidity readings for each room are compared against the targets at the selected intervals of time, and the corresponding differences are fuzzified. These differences are used to decide the fuzzy qualifier, which is decoded into a crisp value that is the change required in the setting of the thermostat of the AC. As a result, each room will maintain a temperature near 25 °C and a relative humidity near 70% while the compressor will remain off for an appreciable period leading to a saving of energy. Though a thermostat with programmable setting for an AC unit dedicated to a single room has been reported in the literature, the same for a central AC unit that serves more than one room appears to have not yet been presented. The advantages of the scheme proposed for programming a thermostat under central air conditioning system are that it (i) requires for each room only a pair of input data i.e. the sensor captured temperature and humidity readings for each room, (ii) controls humidity indirectly and (iii) leads to a saving in energy consumption while maintaining a comfortable level of cooling in each of the rooms though their occupancy, size and the thermal conditions are different from one another.     

Effect of ambient conditions on the first and second law performance of an open desiccant cooling process

An open desiccant cooling process is presented and applied to ventilation and recirculation modes of the system operation. The cooling system consists of a desiccant wheel, a rotary regenerator, two evaporative coolers, and a heating unit. Certain ideal operating characteristics based primarily on the first law of thermodynamics are assumed for each component. The system with indoor and outdoor ARI conditions has a thermal coefficient of performance (COP) of 1.17 in ventilation mode and 1.28 in recirculation mode. A second law analysis is also performed and at ARI conditions, the reversible COP of the system is determined to be 2.63 in ventilation mode and 3.04 in recirculation mode. Variation of the first and second law based COP terms and cooling load with respect to ambient temperature and relative humidity are investigated in both modes of the system operation. The results of the analysis provide an upper limit for the system performance at various ambient conditions and may serve as a model to which actual desiccant cooling systems may be compared. As an additional study, a non-ideal system operation is considered and it is determined that both the COP and cooling load decrease with increasing ambient temperature and relative humidity, and they approach zero at high values of ambient temperature and humidity.     

Study of a new environmental chamber design

The present study develops an environmental chamber for temperature and humidity control (THCS) in which the condenser is divided into two parts. By properly adjusting the fan speeds of the outer and inner condensers, an enclosed chamber can obtain net heating or cooling effect and the temperature and humidity can be directly controlled. The system dynamics of the THCS is first studied. The temperature response models, G₁₁(s) and G₁₂(s), are shown to be of a first order. The humidity response models, G₂₁(s) and G₂₂(s), are of second order with a zero. It is found that the multiple-input-multiple-output (MIMO) control system can be decoupled into a temperature and humidity control loops. A control system using a PI controller is designed and implemented on a PC with an 8051 microprocessor. It has experimentally been shown that the chamber temperature and humidity can be controlled to within ±0.1 °C and ±1% R.H., respectively. In the presence of a heat load disturbance, the controller can restore the THCS to operate at the setting values within a reasonable transient time.     

Discharge air system: modelling and optimal control

A state‐space model of a discharge air system (DAS) is developed. Simulation results obtained from the developed model compare well with the published experimental data. The optimal control strategies and optimal performance of DAS to step changes in setpoints are given for two cases: a heating case with temperature control, and a cooling case with temperature and humidity control. Results show that the outputs (discharge air temperature and humidity ratio) of the system reach the chosen setpoints rapidly and smoothly compared with that of PI control results published in the literature. Copyright © 1999 John Wiley & Sons, Ltd.     

地源热泵间歇运行下土壤热湿迁移的实验研究

建立地埋管换热土壤热湿迁移过程的实验装置,对地源热泵间歇运行时不同进口流体温度及不同土壤体积含水率下土壤温湿度场的变化特性进行实验研究。实验结果表明∶间歇运行时,入口流体温度的升高会使土壤温度最大值升高,但不利于土壤温度的恢复,土壤体积含水率的增加在一定程度上有利于地下换热和土壤温度的恢复。系统开机后存在土壤温度上升的主上升区,此区温度增幅超过65%,关机后第18小时土壤温度基本恢复至初始温度;系统关停后在温湿度梯度的作用下会出现温度和含水率最大值后移的现象,热源对土壤温度和含水率的作用半径约为280和375 mm;开停比为1∶2时温湿度较1∶1能恢复得更低,合理设置停机时间有利于机组长期有效运行。     

基于燃料电池膜水分传递特性研究的温度与湿度控制

质子交换膜燃料电池(PEMFC)中保持膜的适度湿润性非常重要.模拟了质子交换膜的水环境,采用西门子S7-300PLC和力控组态软件设计了温度湿度控制系统;应用PID调节原理分别控制三种不同空气流量(1、6、10 g·s-1)情况下空气加热器和水加热器的温湿度.由数据分析可得到结论:1 g·s-1流量引起的湿度波动较大,10 g·s-1流量在高温高湿情况下出现异常.