scholarly journals Research on Key Parameters Operation Range of Central Air Conditioning Based on Binary K-Means and Apriori Algorithm

Energies ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 102 ◽  
Author(s):  
Liangwen Yan ◽  
Fengfeng Qian ◽  
Wei Li
Keyword(s):  
Optimal Control ◽  
Temperature Difference ◽  
Air Conditioning ◽  
Control Strategies ◽  
Cooling Water ◽  
Apriori Algorithm ◽  
The Third ◽  
Time Optimal ◽  
Central Air Conditioning ◽  
Energy Saving Control

As the energy-saving control of central air conditioning has been widely applied in modern architecture, research of real-time optimal control based on historical data and identification of its optimal control strategies are of great importance for reducing energy wasting of buildings. However, due to the property of easily falling into local optimum, conventional k-means approach cannot achieve the goal of real-time optimal control, we therefore propose an innovative binary k-means clustering algorithm which is used to adjust the target value of temperature difference (TD) in the control system of chilled water and cooling water of central air conditioning system (CACS). Thanks to the clustering control, among the 304 test data, the coefficient of performance (COP) of 211 sets of data, which accounted for 69.41%, are higher than those of the traditional control method. In the simulation system, the COP of 191 sets of data, which accounted for 62.83%, are higher than those of traditional control methods, achieving better energy efficiency. To achieve the goal of identify potential energy-saving control strategies, the Apriori algorithm is proposed to correlate the key parameters and energy consumption efficiency of the CACS. The results show when the chilled water temperature difference (CWTD) > 2.0 °C and the cooling water temperature difference (COWTD) > 2.4 °C, some rules are discovered as follows: 1. The probability of a larger system COP will increase if the CWTD is set lower than the third quartile value or the COWTD is set lower than the first quartile value. 2. The probability of a larger system COP will also increase if the CTWD is set lower than the first quartile and the COWTD is set between the first and the third quartile. These underlying regularity is useful for technicians to adjust the control parameters of the equipment, to improve energy efficiency and to reduce energy consumption.

Distributed real-time optimal control of central air-conditioning systems

2022 ◽  
Vol 256 ◽  
pp. 111756
Author(s):  
Hussain Syed Asad ◽  
Hang Wan ◽  
Hewage Kasun ◽  
Sadiq Rehan ◽  
Gongsheng Huang
Keyword(s):  
Optimal Control ◽  
Real Time ◽  
Air Conditioning ◽  
Time Optimal Control ◽  
Time Optimal ◽  
Central Air Conditioning ◽  
Air Conditioning Systems

Optimal Control Strategy for Ice-Storage System Based on Hourly Dynamic Load Simulation

2013 ◽  
Vol 671-674 ◽  
pp. 2515-2519
Author(s):  
Xue Mei Wang ◽  
Zhen Hai Wang ◽  
Xing Long Wu
Keyword(s):  
Optimal Control ◽  
Air Conditioning ◽  
Control Strategies ◽  
Storage System ◽  
Simulation Software ◽  
Ice Storage ◽  
Optimal Control Strategy ◽  
Air Conditioning System ◽  
Energy Plus ◽  
Load Simulation

This project aims to study the optimal control model of the ice-storage system which is theoretically close to the optimal control and also applicable to actual engineering. Using Energy Plus, the energy consumption simulation software, and the simple solution method of optimal control, researchers can analyze and compare the annual operation costs of the ice-storage air-conditioning system of a project in Beijing under different control strategies. Researchers obtained the power rates of the air-conditioning system in the office building under the conditions of chiller-priority and optimal contro1 throughout the cooling season. Through analysis and comparison, they find that after the implementation of optimal control, the annually saved power bills mainly result from non-design conditions, especially in the transitional seasons.

Investigation and Research of Biological Contamination of HVAC in Public Places

2011 ◽  
Vol 250-253 ◽  
pp. 2719-2722
Author(s):  
Xin Li ◽  
Ya Wei ◽  
Liang Li
Keyword(s):  
Public Health ◽  
Air Conditioning ◽  
Ventilation System ◽  
Cooling Water ◽  
Public Places ◽  
Biological Contamination ◽  
Central Air Conditioning ◽  
Normal Method ◽  
Number Of Bacteria ◽  
Public Health Standard

According to the normal method for sampling in the appendix of “The Central Air-Conditioning Ventilation System of Public Health Standard” by the ministry of health in 2006 were the HVAC on-site examined and sampled. The examined indicators include: total number of bacteria, fungus and beta Streptococcus in air supplied outlet, Legion Ella pneumophila in cooling water, the quantity of dust and microbe amounts to each square meter pipeline surface area and other sanitation indexes.

Energy Saving Control System for Central Air-Conditioning Based on Terminal Temperature Measuring and Frequency Conversion Control Technology

2011 ◽  
Vol 201-203 ◽  
pp. 2144-2153
Author(s):  
Hong Yu Zhou ◽  
Xiao Jian Chen ◽  
Zi Hu Chen ◽  
Ming Wei Tong
Keyword(s):  
Control System ◽  
Energy Saving ◽  
Air Conditioning ◽  
Frequency Conversion ◽  
High Energy ◽  
Control Technology ◽  
Water Pump ◽  
Temperature Measuring ◽  
Central Air Conditioning ◽  
Energy Saving Control

In view of the insufficiency of central air-conditioning system that FCU, water pumps and air blower’s movement connot match with the actual operating load when varying duty, an energy saving control system for central air-conditioning based on terminal temperature measuring and frequency conversion control technology is proposed. This system can real-time measure different floors’ and nods’ temperatures in the building, and export orders to control the frequency of FCU, chilled water pump, cooling water pump and cooling tower air blower. To overcome big delay, large inertia and variable condition of control object, the dnamic fzzy nural network algorithm(DFNN), is applied into the control system. According to the practical running situations, the energy saving control system has advantages as high energy saving rate, high stability, good maintainability, which may be promoted the application vigorously.

Application of the Self-Adjusting Fuzzy Control in Water System of Central Air-Conditioner for Saving Energy

2014 ◽  
Vol 1070-1072 ◽  
pp. 2010-2016 ◽  
Author(s):  
Yuan Yuan Zhang ◽  
Yu Nong Shen
Keyword(s):  
Air Conditioning ◽  
Fuzzy Controller ◽  
Control Strategies ◽  
Water System ◽  
Response Speed ◽  
The Self ◽  
Air Conditioner ◽  
Air Conditioning System ◽  
Central Air Conditioning ◽  
Saving Effect

Central air conditioning system with multi variable, nonlinear, time-varying, large time-delay characteristics using the traditional control strategy is difficult to control and good energy saving effect. For these features of central air conditioning system, self-adjustment fuzzy controller is studied based on the fuzzy controller. The simulation can be seen, the self-adjustment fuzzy controller has a faster response speed and smaller steady-state error, while there is a certain adaptive capacity. Its control performance is superior to conventional control strategies and conventional fuzzy controller. Central air-conditioning system uses the parameter self-adjusting fuzzy controller strategy combined with inverter technology. According to load changes, central air conditioning water system can automatically real-timely control the pumps to ensure that the comfort of central air-conditioning provided a significant reduction in energy consumption.

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