A Hybrid Dynamical Modelling and Control Approach for Energy Saving of Central Air Conditioning

Abstract

Currently in China, energy conservation and emission reduction are important initiatives for society. Because of its large proportion of building energy consumption, several methods for building energy conservation have been introduced for central air conditioning. This paper presents a hybrid system for a modelling and control approach. By analysing the cooling capacity transfer process and the electromagnetic properties of pumps, the modelling is performed in a hybrid system framework. Pumps are classified as fixed-frequency pumps, variable-frequency pumps, and switchable pumps; a switch control strategy is used in the chilled water system for supplying cooling capacity. In order to adjust indoor temperature and save electrical energy, the cooling capacity allocation and average temperature methods are presented, which satisfy the goal of optimal control of real-time energy consumption. As a numerical example, the temperature variation and cold regulation processes are simulated. Three rooms are the control objects that lower the setting points, and pumps waste as little electrical energy as possible. The results show 49.4% of water pump power consumption when compared with constant water volume technology. The modelling and control approach is more advantageous in ensuring the success of reconstruction projects for central air conditioning.

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

“…In chilled water system, switching and variable frequency behaviors of pumps adjust the flow for saving energy, which denote the discrete and continuous time process, respectively. So we give an equation to show the heat balance as follows [34]:…”

Heat Load Calculation with Duct Design of a Multi Storeyed Residential Building

“…In the paper "A comfort-Aware Energy Efficient HVAC System based on the Subspace Identification Method", deals with the effective way to decrease the energy required for HVAC system by identifying the subspace [7].…”

An Optimal Hybrid Control Method for Energy-Saving of Chilled Water System in Central Air Conditioning

“…Set the state variable ( ) = ( ) and the input variable ( ) = w ( ), use the variable water volume of water system and the constant air volume of air system transfer modes [3,13], and use the differential equation to describe the system model:(…”

“…Compared with the rate, an online optimization control strategy is proposed, and the performance improvement is demonstrated through experiments. Zhang Yan et al [13] proposed a kind of central air-conditioning cooling based on hybrid system model. The model of energy saving in the frozen water system, and set the action of the pump group for frequency conversion and switching, and demonstrate the applicability of the model and control strategy through computer simulation; H. Wang et al [14] put various energy saving such as variable flow, temperature difference and differential pressure.…”