Use of evolutionary strategies to develop an adaptive fuzzy logic controller for a cooling coil

In this paper, an evolutionary strategy approach is presented for tuning an AFLC to control the outlet temperature of a cooling coil. Two different methods, modifying scaling factors and modifying fuzzy membership functions, are studied. The simulation and real-time tests showed that evolutionary strategy techniques work well for evolving these AFLC parameters.     

Use of genetic algorithms to develop an adaptive fuzzy logic controller for a cooling coil

An adaptive approach to control a water valve for a cooling coil, called an adaptive fuzzy logic controller (AFLC), is developed and validated in this study. The AFLC calculates the error between the supply air temperature and the supply air temperature set point for air in an air handling unit (AHU) of a heating, ventilating, and air conditioning (HVAC) system and continues to improve the fuzzy controller parameters to minimize the error. The AFLC uses genetic algorithms (GAs) to improve the fuzzy rule matrix and fuzzy membership functions for the AHU in HVAC systems. In this paper, the application of genetic algorithms for developing the AFLC is presented. After a brief background on fuzzy logic controllers and GA theory, the use of GAs is explained. Three methods of modifying the fuzzy rule matrix using the GAs are presented along with simulation and real-time experimental results. Experimental results indicate that GAs can be successfully applied to modify an AFLC rule matrix to achieve a better controller.     

Development of an adaptive Smith predictor-based self-tuning PI controller for an HVAC system in a test room

This paper presents an adaptive Smith predictor-based self-tuning PI controller and its application to the air-conditioning system of a test room. The significant time delay of air-conditioning processes can lead to degradation of performance and instability of the control loop. The parameters of air-conditioning processes vary due to the changes in the operation conditions. By using a recursive least squares (RLS) algorithm combined with a z-domain fitting method, the parameters of the air-conditioning process in the closed loop including time delay can be estimated online. Based on the estimated dead-time, a Smith predictor, which uses a reference model, is adopted to reduce the unfavorable effects of the time delay in the air-conditioning system. Based on the predicted error and estimated values, the control signal of the control loop is calculated by a self-tuning PI controller using ITAE tuning rules. The performance, robustness and effectiveness of the proposed control method are validated in the experimental platform. The corresponding performance of the proposed control method is compared with an adaptive PI controller. Experiment results demonstrate that the proposed strategy achieves better performance compared with the adaptive PI controller considering the effects of set-point changes, parameter variations or load disturbances in HVAC systems.     

南京某别墅温湿独立控制空调系统的设计

地源热泵联合毛细管网辐射末端应用于别墅中,能够结合二者的优点,充分利用低品位能源,节能效果显著。毛细管网辐射末端配合置换通风系统实现了温湿度的解耦,毛细管网承担几乎全部的显热负荷,新风系统承担潜热负荷,做到温湿度独立控制,能够创造超高的热舒适性和室内环境品质。防结露控制系统通过实时的温湿度监测和流量调节,避免房间结露,保障了系统正常运行。热回收系统为别墅提供基本生活热水,不仅平衡了负荷,而且进一步提高了能源的综合利用效率。     

某市地下人防建筑通风空调设计

分析了地下人防建筑在年温度波衰减、围护结构蓄热、围护结构气密性等方面的特点，介绍了其通风空调系统的设计计算方法，给出了该市地下人防商场的冷负荷指标。     

CFD模拟在某游泳馆通风空调设计中的应用

在杭州某游泳馆通风空调设计中，为了考察围护结构内表面的结露情况，利用简化的模型进行了CFD数值模拟。本文介绍了这次数值模拟过程，并根据模拟结果分析比较了设计相对湿度不同的两个方案，模拟结果显示，设计相对湿度较小的方案比较经济。本文的模拟结果也可为类似工程的空调设计方案选择提供一定的参考。