VEHICLE AIR CONDITIONER (VAC) CONTROL SYSTEM BASED ON PASSENGER COMFORT: A PROOF OF CONCEPT

The air conditioning system (AC) in passenger cars requires precise control to provide a comfortable and healthy driving. In an AC system with limited manual control, the driver has to repeatedly change the setting to improve comfort. This problem may be overcome by implementing an automatic control system to maintain cabin temperature and humidity to meet passenger's thermal comfort. Therefore, this paper presents the development of a laboratory-scale prototype air conditioning control system to regulate temperature, humidity and air circulation in the cabin. The experimental results show that the control system is able to control air temperature in the range of 21 °C to 23 °C and cabin air humidity between 40% to 60% in various simulated environmental conditions which indicate acceptance for comfort and health standards in the vehicle. In conclusion, this method can be applied to older vehicles with reasonable modifications. ABSTRAK: Sistem penyejuk udara (AC) pada kenderaan penumpang memerlukan ketepatan kawalan bagi menyediakan keselesaan dan kesejahteraan pemanduan. Melalui sistem AC dengan kawalan manual terhad, pemandu perlu berulang kali mengubah penyesuaian latar bagi meningkatkan keselesaan. Masalah ini dapat diatasi dengan menerapkan sistem kawalan automatik bagi menjaga suhu dan kelembapan kabin agar memenuhi keselesaan suhu penumpang. Oleh itu, kajian ini merupakan pembangunan prototaip sistem kawalan AC skala laboratari bagi mengawal suhu, kelembapan dan peredaran udara dalam kabin. Hasil eksperimen menunjukkan sistem kawalan ini mampu mengendali suhu udara pada kitaran 21 °C hingga 23 °C dan kelembaban udara kabin antara 40% hingga 60% pada pelbagai keadaan persekitaran simulasi yang menunjukkan penerimaan standard keselesaan dan kesejahteraan kenderaan. Sebagai kesimpulan, cara ini dapat diaplikasi pada kenderaan lama dengan modifikasi bersesuaian.

Investigation of the Effect of Solar Ventilation on the Cabin Temperature of Vehicles Parked under the Sun

During hot days, the temperature inside vehicles parked under the sun is very high; according to previous studies, the vehicle cabin temperature can be more than 20 °C higher than the ambient temperature. Due to the greenhouse effect, the heating that occurs inside a vehicle while it is parked under the sun has an impact on energy crises and environmental pollution. In addition, the increase in the temperature inside the cabin will have an effect on the dashboard and plastic accessories and the leather on the seats will age rapidly. The ventilation of solar energy from the cabin of a vehicle parked under the blazing sun has received a great deal of attention. The present study was conducted to utilize a renewable energy system to operate the ventilation system through a novel portable ventilation system powered by solar energy. Experimental results were obtained for a vehicle with and without the solar ventilation system. The results indicate that the maximum daily average difference in temperature during the experimental tests between the cabin of the car and the atmospheric temperature with and without the solar ventilation system was 7.2 °C and 20.6 °C, respectively. With and without the usage of the system, the minimum average difference in temperature between the automobile’s cabin and the atmospheric temperature was 6.2 °C and 17.6 °C, respectively. The results indicate that the proposed system is effective and that the thermal comfort inside the vehicle’s cabin improved when the vehicle was parked under the hot sun. Therefore, this system helps to protect human bodies, conserve energy, protect the environment, protect the vehicle’s cabin, and provide a comfortable environment.

INCREASED PRODUCTIVITY OF LIQUID SMOKE THROUGH FAST THAWING WITH REFRIGERATION SYSTEMS AT LOW AIR TEMPERATURE

Liquid smoke increased in demand by the community because it is made from environmentally friendly waste can directly reduce the impact of environmental pollution. The smoke condensing process that is carried out conventionally using water can be continuously replaced using a refrigeration system, the smoke condensation process can be carried out using controlled low-temperature air, this can minimize machine space and energy. In this study, an analysis of variations in air temperature will be carried out to maximize the productivity of liquid smoke. The raw material for palm kernel shell is -4 + 5 mesh with cabin temperature variations of 15-10°C, 10-5°C, and 5-0°C and pyrolysis temperature of 300-400°C. Based on the research results obtained maximum results at a temperature of 5-0°C with 23.6% liquid smoke, 3.7% tar, 63.8% charcoal, and 8.9% gas. Based on the test results of chemical compounds, liquid smoke has an average phenol value of 56.59%. The lower the air temperature used to condense the smoke, the maximum liquid smoke will be and the less gas escapes to the air. It can directly reduce air pollution in the process of making liquid smoke.

Cooling system based on double-ball motor control valve

To realize eco-models based on (where 3R represents reducing, reusing, and recycling), both researchers and automobile development departments use controllable components to reduce vehicle fuel consumption and emissions. In this context, this paper presents the design of a double-ball motor control valve (DB-MCV). When compared with use of a traditional thermostat, use of the proposed valve in a Worldwide Harmonized Light Vehicles Test Cycle (WLTC) allows the coolant temperature to be controlled accurately as per the vehicle operating conditions, with control accuracy of ±1°C. Using this approach, the engine pre-heating time is reduced by 61 s, the total hydrocarbon (THC)) emission is reduced by 6.79%, the CO emission is reduced by 7.18%, and NOX emission is reduced by 4.84%. Under the same vehicle and working conditions, the engine fuel consumption is reduced by 2.31% on average. Under the cabin heating condition, the cabin temperature can be increased by 4.3°C, which improves the thermal comfort of the driver. When the vehicle is stopped after running at high speed and the engine is idling, the coolant temperature in the engine decreases rapidly, which reduces the risk of a hot dip occurring in the engine.

Experimental Study of Thermal Comfort Based on Driver Physiological Signals in Cooling Mode under Summer Conditions

In this study, electroencephalogram (EEG), photo-plethysmography (PPG), and surface temperature measurements of subjects were taken while performing a driving simulation when the cabin and vent discharge air temperature in summer were changed from discomfort to comfort conditions. Additionally, subjective questionnaires were used to analyze the subject’s thermal comfort under the various driving environments. As a result, the surface temperatures of the forehead, left hand, right hand, and abdomen of the subject during driving were reduced by 2, 0.97, 2.18, and 5.86 °C, respectively, by operating a 12.5 °C vent cooling function at a cabin temperature of 35 °C. As a comprehensive analysis of the subjective survey, PPG, and EEG results, total power (TP), the standard deviation of N-N interval (SDNN), and the root mean square of successive differences (RMSSD) of subjects increased and stress index decreased at cabin and vent discharge air temperatures of 30–27.5 °C and 16.5–18.5 °C, respectively. Furthermore, the relative sensory motor rhythm (SMR) wave and concentration index (CI) of the frontal lobe tended to increase under the same temperature conditions. Accordingly, it was confirmed that these temperature conditions provided a pleasant driving environment for the driver and increased concentration on driving.