An Innovative Design of Regional Air Conditioning to Increase Automobile Cabin Energy Efficiency

Abstract

With the goal of increasing energy efficiency and passenger comfort in an automobile cabin, we developed a regional air-conditioning design to control cold air in specific regions, and an air management strategy that can keep air circulation when the car engine cuts out. According to computational simulations, an air velocity of 2 m/s was adopted, which could form an independent flow field space in the cabin with a temperature gap of 7 °C according to the user’s needs. The designed regional air-conditioning and circulation system could create independent flow field spaces with temperature differences. Inlet air volume demand was also reduced by 60% and blower power by 53 W. In addition, the cabin ventilation system led air exchange rate reached 89% per hour. In 20 min of exposure under sun, the system could lower the cabin temperature by 12.3 °C.

Theoretical studies of the heating system in the vehicle compartment during passenger transportation taking into account breathing under conditions of low temperatures

“…Accordingly, the scheme under consideration for heating the passenger compartment does not provide real thermal comfort for passengers. To ensure the thermal comfort of each passenger of the vehicle compartment, a more complex system of microclimate parameters regulation is needed, as is proven in papers [6,27,33]. From the comparison of Figures 4 and 8, it follows that the effect of passengers' breathing in the considered design of the vehicle does not have a signifi cant impact on the temperature distribution in the compartment space, which can be caused by the fact that the difference between the initial temperature of exhaled air and body temperature was not great and was 1 ºC.…”

“…The development of microclimate regulation systems is presented in papers [8,21,27,28], and the assessment of their performance by such indicators as energy consumption, thermal comfort and air quality is presented in papers [6,12,13,29,30,31,32,33]. Theoretical studies of microclimate regulation systems and microclimate effect on humans are based on computer models described in papers [3,5,7,9,10,25,27,28,29,33]. The papers [35,36] provide a comparative analysis and assessment of the possibilities of various implementations of mathematical models of gas thermodynamics on computers.…”

“…The increase in accuracy of the thermodynamic model implementations on the computer is provided due to the congruence of 3D models, the use of advanced computational algorithms and taking into account all participants in the heat balance creation, according to papers [31,33,38]. Thus, accounting for friction and aerodynamic forces in providing thermal comfort is discussed in paper [32], and the role of solar radiation and radiation of the interior panels is discussed in papers [11,27,31]. In paper [39] a description of the main parameters of the microclimate in the car compartment and the factors inherent to passengers are presented.…”

“…It has been established that the parameters of microclimate in the compartment during movement are not constant, as well as subjective sensations of thermal comfort are different when the vehicle is moving and when it is motionless, as demonstrated in papers [11,16,17]. However, almost all papers consider the thermal comfort provision in conditions of heating microclimate which can be found in papers [9,10,12,15,17,18,19,25,27,29,31,33]; at the same time passengers represent passive receptors in the context of the environment, as is proven in paper [43]. Therefore, assessment of heating system effi ciency under conditions of cooling microclimate in the cold period of the year and determination of actual values of microclimate parameters in the compartment for wheeled vehicles of M3 category with the seating capacity not exceeding 22 passengers, taking into account the external respiration of a person as a constituent element in providing thermal comfort, is one of the further research trends in regulation of microclimate of the passenger compartment of the wheeled vehicle.…”

Dynamic Modelling and Performance Prediction of a Multi-unit Baseline Air Conditioning System for a Generic Bus under Part-Load Conditions

“…On top of that, these studies can be categorized into two main groups based on whether the emphasis is on the cooling system or just indoor space. In fact on one hand, some studies have emphasized the thermal modelling of indoor/cabin spaces trying to evaluate the thermal loads and the comfort condition by means of detailed CFD (Computational Fluid Dynamics) [5,9,10,11] or lumped-parameter models. For example, Marcos et al [2] developed a thermal model of the cabin in passenger vehicles using Simulink-MATLAB.…”