Modeling and Simulation of Chilled Water System for Central Air Conditioning

2012 ◽  
Vol 204-208 ◽  
pp. 4280-4285 ◽  
Author(s):  
Jian Min Sun ◽  
Chun Dong Zhang ◽  
Ze Yang Zhou
Keyword(s):  
Control System ◽  
Energy Saving ◽  
Pid Control ◽  
Air Conditioning ◽  
Water System ◽  
Air Conditioning System ◽  
Chilled Water ◽  
Central Air Conditioning ◽  
Chilled Water System ◽  
Saving Effect

Considering the central air conditioning system is highly susceptible to interferences from external environment, this paper established a dynamic mathematical model for chilled water system with the air conditioning area, fan coil unit and air conditioning area interference factors. Selection of chilled water system as a controlled object, designed the energy saving control system for central air-conditioning. The inputs of PID controller are deviation of actual temperature and setting temperature, and the change rate of the deviation; output is operation frequency of pump. Experiment shows that, PID control system in 90% time operating at a frequency of 10Hz-40Hz, average is 32.5Hz. Compared with no control system, the pump power consumption was reduced 33.9%.In conclusion, PID control in the central air conditioning system have a good energy saving effect.

Energy-Saving Monitoring System of Central Air-Conditioning Based on Dynamic Load

2014 ◽  
Vol 1039 ◽  
pp. 409-414
Author(s):  
Tao Han ◽  
Xue Feng Lai ◽  
Liang Wen Yan ◽  
Zai Feng Zhang
Keyword(s):  
Energy Saving ◽  
Monitoring System ◽  
Dynamic Load ◽  
Pid Control ◽  
Air Conditioning ◽  
Water System ◽  
Air Conditioning System ◽  
Advantages And Disadvantages ◽  
Hardware System ◽  
Central Air Conditioning

This paper introduces the components of central air-conditioning system and compares the advantages and disadvantages of the PID control and fuzzy control.Fuzzy control theory and inverter technology are combined to design the Energy-Saving Monitoring System based on the fuzzy control box of STM32F103C8T6,Siemens S7-200 PLC, ABB inverter as the hardware system and interfaces configuration of KingView as the software. Experimental results show that the water system can be variable flow controlled based on the dynamic load, central air-conditioning energy efficiency the COP has greatly improved under the premise of ensuring the comfort of central air-conditioning.

scholarly journals A Modelling and Control Approach for a Type of Mixed Logical Dynamical System Using in Chilled Water System of Refrigeration System

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Yan Zhang ◽  
Xiaoli Chu ◽  
Yang Liu ◽  
Yongqiang Liu
Keyword(s):  
Energy Saving ◽  
Hybrid System ◽  
Air Conditioning ◽  
Water System ◽  
Cooling Capacity ◽  
Chilled Water ◽  
Central Air Conditioning ◽  
Chilled Water System ◽  
And Control ◽  
Mixed Logical Dynamical

The chilled water system of central air conditioning is a typical hybrid system. The dynamic adjustment of cooling capacity based on hybrid system can achieve accurate temperature control and real-time energy saving. Mixed logical dynamical (MLD) systems have advantage for solving constrained optimization problems of this type of case by numerical methods. This paper proposes a novel modified type of MLD system, which enhances the model applicability and improves the switching flexibility and control effect for the framework. In order to meet the needs of cooling capacity and energy saving, the optimal control problem is transformed as MIQP problem by defined performance index. As a numeral example of application, the model and control method is used in pumps group control for variable water volume in chilled water system of central air conditioning. At last, the dynamic and energy-saving effects of the system are simulated, which shows the ideal control results.

Air Conditioning System Water Quality and Equipment Condition Investigation and Analysis of Energy Saving Measures

2012 ◽  
Vol 516-517 ◽  
pp. 1224-1228
Author(s):  
Na Liang ◽  
Rui Li
Keyword(s):  
Energy Saving ◽  
Air Conditioning ◽  
Water System ◽  
Building Energy ◽  
Development Trend ◽  
Air Conditioning System ◽  
Effective Utilization ◽  
Energy Saving Potential ◽  
Central Air Conditioning ◽  
Points Of View

Due to energy reserves reduces gradually and uneven distribution, all countries pay more and more attention to energy saving and improve the effective utilization of energy, China also attaches great important to this. Energy saving of buildings is a necessary development trend. Air conditioning system as a large important part of building energy consumption has a huge energy-saving potential. This article mainly introduced the related strategies of energy saving in central air conditioning water system from the following three points of view: the water treatment, the cooling tower, and the variable frequency pump.

Mixed Programming Using FORTRAN and VB of Pipe Network for Heating and Air Condition Water System

2012 ◽  
Vol 610-613 ◽  
pp. 2478-2482
Author(s):  
Yang Cui ◽  
Lei Huang
Keyword(s):  
Air Conditioning ◽  
Simulation Analysis ◽  
Water System ◽  
Pipe Network ◽  
Air Conditioning System ◽  
Mixed Programming ◽  
Simulating Analysis ◽  
Chilled Water ◽  
Fortran Language ◽  
Chilled Water System

As the scale of the air conditioning system is constantly increasing, some problems still exist and remain to be solved in the chilled water system. Among them, the leading problems lie in the insufficient research of the overall character on the user side and lack of simulation analysis. Corresponding calculating procedures are mixed programmed using VB and FORTRAN language to conduct to simulating analysis, to testify reliability and feasibility of the method.

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.

Application Analysis of Chilled Water Storage Technology in the Transformation of Central Air Conditioning System

2012 ◽  
Vol 608-609 ◽  
pp. 1097-1105
Author(s):  
Kai Jing Liu ◽  
Qun Li Zhang ◽  
De Ying Li
Keyword(s):  
Air Conditioning ◽  
Water Storage ◽  
Cost Comparison ◽  
Air Conditioning System ◽  
Storage Technology ◽  
Application Analysis ◽  
Chilled Water ◽  
Central Air Conditioning ◽  
Saving Effect ◽  
Operation Cost

This article introduces the specific application of central air conditioning chilled water storage technology in the actual central air conditioning engineered reconstruction. The author analyzes the energy-saving effect of application of central air conditioning chilled water storage technology and the economy of central conditioning renovation project. Operation cost comparison shows that water storage air conditioning system saves money more above 35% than conventional air conditioning system.

Research on Central Air Conditioning System of Intelligent Buildings

2014 ◽  
Vol 960-961 ◽  
pp. 639-642
Author(s):  
Xue Jing Sun
Keyword(s):  
Control System ◽  
Pid Control ◽  
Air Conditioning ◽  
Air Conditioning System ◽  
Pid Algorithm ◽  
Intelligent Buildings ◽  
Central Air Conditioning ◽  
Set Up ◽  
Control Principle ◽  
Conditioning Control

In this paper, microcontroller is applied in the central air conditioning control system. Firstly, microcontroller controller is used as controlling core to control temperature and humidity of central air conditioning control system. Secondly, PID algorithm parameters are set up for improving traditional PID control principle. Lastly, input and output values can be set and displayed by LCD screen.

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