scholarly journals Towards energy efficient operation of Heating, Ventilation and Air Conditioning systems via advanced supervisory control design

2015 ◽  
Vol 659 ◽  
pp. 012030
Author(s):  
A Oswiecinska ◽  
J Hibbs ◽  
I Zajic ◽  
K J Burnham
Keyword(s):  
Supervisory Control ◽  
Energy Efficient ◽  
Air Conditioning ◽  
Control Design ◽  
Efficient Operation ◽  
Air Conditioning Systems

Effect of Air Conditioning Position on Thermal Comfort in the Floor Air Conditioning System

2014 ◽  
Vol 493 ◽  
pp. 74-79
Author(s):  
Y.A. Sabtalistia ◽  
S.N.N. Ekasiwi ◽  
B. Iskandriawan
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Energy Consumption ◽  
Thermal Comfort ◽  
Energy Efficient ◽  
Air Conditioning ◽  
Air Conditioning System ◽  
Air Supply ◽  
Air Conditioning Systems ◽  
Air Diffusion

Energy consumption for air conditioning systems (air conditioning system) increased along with the increasing need for fresh air and comfortable in the room especially apartments. FAC system (Floor Air Conditioning) is growing because it is more energy efficient than CAC (Ceiling Air Conditioning) system. However, the position of the AC supply is on the lower level at the FAC system causes draft discomfort becomes greater as air supply closer to the occupants so that thermal comfort can be reduced. Heat mixture of windows, exterior walls, kitchen, and occupants in the studio apartment affect thermal comfort in the room too.This study aims to determine the position of the AC supply which has the best thermal comfort of FAC system in the studio apartment. It can be done by analyzing ADPI (Air Diffusion Performance Index), the distribution of air temperature, wind speed, RH (Relative Humidity), and DR (Draft Risk) to change the position of the AC supply supported by CFD (Computational Fluid Dynamics) simulation.This result prove that AC position 2 (on wall near the kitchen) is more comfortable than AC position 1 (on the bathroom wall) because AC position 2 away from occupied areas, thereby reducing the occurrence of draught discomfort.

scholarly journals Calculation of marine air conditioning systems based on energy savings

2017 ◽  
Vol 11 (21) ◽  
pp. 103
Author(s):  
Ricardo A. Lugo-Villalba ◽  
Mario Álvarez Guerra ◽  
Bienvenido Sarria López
Keyword(s):  
Air Conditioning ◽  
Energy Savings ◽  
Waste Heat ◽  
Cooling Capacity ◽  
Efficient Operation ◽  
Average Value ◽  
Economic Operation ◽  
International Policies ◽  
Need To Evaluate ◽  
Air Conditioning Systems

The development of ship propulsion in the areas of Economic Operation, Environmental Protection and Ship Efficiency (Triple E - Economy, Environment, Efficiency) is the comparison standard of the manufacturers of contemporary ships. The standard is based on the application of a more modern design of the diesel engines, the wide use of waste heat and the efficient operation of the ship.In accordance with the Economic Operation, the need to evaluate the design of air conditioning systems has been identified in order to determine the possible savings, which are represented by a decrease in fuel consumption, as a result of: the significant impact of this consumption in the operation of the ship, the current high costs of this energy, the periodic increase in the price of the same, and the international policies for the reduction of emissions to the atmosphere and preservation of the environment.By means of the energy diagnosis of the air conditioning system it is possible to determine the possible opportunities of energy saving during the operation of the ship.The results indicate that the thermal load and the cooling capacity required by the air conditioned spaces have a difference between their maximum and average value of 14%. This justifies the need to use a conditioning system with a variable volume of air supplied to the air conditioned space.

scholarly journals Experimental analysis of fuzzy controlled energy efficient demand controlled ventilation economizer cycle variable air volume air conditioning system

2008 ◽  
Vol 12 (3) ◽  
pp. 15-32 ◽  
Author(s):  
Parameshwaran Rajagopalan ◽  
Karunakaran Rajasekaran ◽  
Senthilkumar Alagarsamy ◽  
S. Iniyan ◽  
Mohal Lal
Keyword(s):  
Fuzzy Logic ◽  
Energy Efficient ◽  
Air Conditioning ◽  
Test Results ◽  
Air Conditioning System ◽  
Variable Air Volume ◽  
Controlled Ventilation ◽  
Air Volume ◽  
Demand Controlled Ventilation ◽  
Air Conditioning Systems

In the quest for energy conservative building design, there is now a great opportunity for a flexible and sophisticated air conditioning system capable of addressing better thermal comfort, indoor air quality, and energy efficiency, that are strongly desired. The variable refrigerant volume air conditioning system provides considerable energy savings, cost effectiveness and reduced space requirements. Applications of intelligent control like fuzzy logic controller, especially adapted to variable air volume air conditioning systems, have drawn more interest in recent years than classical control systems. An experimental analysis was performed to investigate the inherent operational characteristics of the combined variable refrigerant volume and variable air volume air conditioning systems under fixed ventilation, demand controlled ventilation, and combined demand controlled ventilation and economizer cycle techniques for two seasonal conditions. The test results of the variable refrigerant volume and variable air volume air conditioning system for each techniques are presented. The test results infer that the system controlled by fuzzy logic methodology and operated under the CO2 based mechanical ventilation scheme, effectively yields 37% and 56% per day of average energy-saving in summer and winter conditions, respectively. Based on the experimental results, the fuzzy based combined system can be considered to be an alternative energy efficient air conditioning scheme, having significant energy-saving potential compared to the conventional constant air volume air conditioning system.

Uncertainty shift in robust predictive control design for application in CAV air-conditioning systems

2011 ◽  
Vol 32 (4) ◽  
pp. 329-343 ◽  
Author(s):  
Gongsheng Huang ◽  
Tin-Tai Chow
Keyword(s):  
Air Temperature ◽  
Predictive Control ◽  
Air Conditioning ◽  
Prediction Models ◽  
Control Design ◽  
Pi Control ◽  
Control Law ◽  
Original Design ◽  
Input Structure ◽  
Air Conditioning Systems

Constant-air-volume (CAV) air-conditioning systems consist mainly of two local processes: an air-handling process and a room temperature process. A robust model predictive control (RMPC) strategy was developed for CAV air-conditioning systems, which adopted two uncertain first-order plus time-delay models to describe the dynamics of the local processes and used a linear matrix inequality (LMI)-based optimisation technique to optimise the control law. This paper develops a new control design, which reformulates the prediction models by shifting the uncertainties of the first model into the second one, and then uses the reformulated prediction models in the RMPC strategy. This paper will show that compared with the original design, the new control design can enhance the feasibility of the optimisation of control law, reduce the computational burden of the optimisation and also remove the requirement of a sensor for supply air temperature in the original design. Practical applications: The new design method is a further development of a RMPC strategy presented in Xu et al.13 It inherits the benefits of the original control design for practical application, i.e. uncertainties and constraints can be dealt with simultaneously in the design and the robustness of the controlled system can be enhanced. The new design improves the optimisation feasibility, reduces the computational complexity and does not need to measure the supply air temperature. When the new design is adopted to replace the traditional PI control, there is no necessity to change the existent input structure of the PI control. Hence, the new design can be realised in practice easier than the original design.

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