Afiq Aiman Dahlan

The Effect of Ambient Temperature on the Performance of Automotive Air-Conditioning System

The automotive air conditioning is one of the important things to be discovered and analyses to maximize the coefficient of performance (COP). The effects of the global warming in a surrounding world give a big impact on performance of air conditioning system in the vehicle. The significant of these issues make the ambient temperature changing. The ambient temperature it’s different according to the type of the place. The different ambient temperature will effect on the performance of air conditioning system. This study will analysis the energy consumption, temperature distribution and COP at various ambient temperature (30, 35 and 40°C), internal heat load (0, 500,700 and 1000 W) and engine speed (1000, 1500 and 2000 rpm) using HFC-R134a as the refrigerant. Measurements were taken during the 30 minute experimental period for temperature set point which 21°C. The results showed that the performance of the automotive air conditioning system decreases when ambient temperature, internal heat load and compressor speed increased.

Performance Analysis for Vehicle Air Conditioning System with Direct Current Compressor in Non-Electric Vehicle Using Fuzzy Logic Controller

Reducing fuel consumption and ensure occupants thermal comfort are two important considerations when designing a vehicle air conditioning system. By using direct current electric compressor, speed of compressor can be controlled by changing the frequency of the inverter. Fuzzy logic controller (FLC) was developed to imitate the performance of human expert operators by encoding their knowledge in the form of linguistic rules. The system is installed to a 5-door compact car with 1.2cc four-cylinder engine with data acquisition system to monitor the temperature of the cabin, coefficient of performance (COP) and fuel consumption. Temperature set-point of 22°C with original belt-driven, on/off and FLC electric direct current compressor at one hour experimental periods. The experimental results indicate that the FLC can save more fuel compared to on/off controller and belt-driven compressor.

Performance of Automotive Air-Conditioning System by Using Ejector as an Expansion Device

An automotive air conditioning system that uses thermal expansion valve (TEV) as an expansion device. The pressure drop from the condenser and evaporator pressure is considered an isenthalpic process (constant enthalpy), where this process causes energy loss (entropy generation) in the expansion process. The ejector recovers energy losses, which was previously lost in the expansion valve, and an ejector can be used to generate isentropic condition in the expansion process. The use of an ejector as an expansion device in this study can reduce power consumption of the compressor and increase cooling capacity of the evaporator. The experiments were conducted with temperature set-points of the conditioned space of 21, 22 and 23°C with internal heat loads of 100, 200 and 400 W. Measurements were taken during the one hour experimental period at a time interval of five minutes. The experiment results indicate that the ejector system is better than TEV and save fuel.

Impact of the electric compressor for automotive air conditioning system on fuel consumption and performance analysis

Air conditioning system is the biggest auxiliary load in a vehicle where the compressor consumed the largest. Problem with conventional compressor is the cooling capacity cannot be control directly to fulfill the demand of thermal load inside vehicle cabin. This study is conducted experimentally to analyze the difference of fuel usage and air conditioning performance between conventional compressor and electric compressor of the air conditioning system in automobile. The electric compressor is powered by the car battery in non-electric vehicle which the alternator will recharge the battery. The car is setup on a roller dynamometer and the vehicle speed is varied at 0, 30, 60, 90 and 110 km/h at cabin temperature of 25°C and internal heat load of 100 and 400 Watt. The results shows electric compressor has better fuel consumption and coefficient of performance compared to the conventional compressor.

Driving efficiency through hydrocarbon for green car air conditioning

The feasibility of hydrocarbon mixtures to replace HFC-R134a in automotive air conditioning systems is investigated in this paper. The temperature distribution in car cabin and fuel consumption are evaluated at various passenger load and vehicle speeds using hydrofluorocarbons refrigerant (HFC-R134a) and hydrocarbon refrigerant as the working fluid of the compressor. The experiments are tested in an actual petrol engine vehicle on a roller dynamometer to simulate actual vehicle on level road. The experiments are conducted at the same surrounding conditions. The test has performed by varying the vehicle speed; 50, 70, 90 and 110 kph, and number of passengers; 1 and 2, at temperature set-point of 21°C. The result shows that the hydrocarbon mixtures provide excellent temperature distribution and fuel conservation effect is about 2.95% to 11.90%. In addition, the results support the possibility of using hydrocarbon mixtures as an alternative to HFC-R134a in the automotive air conditioning system, without the necessity of changing parts in the current system.

Experimental study on the replacement of HFC-R134A by hydrocarbons in automotive air conditioning system

The HFC-R134a and hydrocarbon refrigerant (HCR) will be evaluated on the automotive air conditioning (AAC) experimental test rig which completed with the AAC system including the blower, evaporator, condenser, radiator, electric motor, compressor, alternator and equipped with the simulation room acting (equipped with internal heat load) as the passenger compartment. The electric motor operated as a car’s engine and will drive the compressor simultaneously to the alternator to recharge the battery. The tests have been performed by varying the motor speed; 1000, 2000 and 3000 rpm, temperature set-point; 21 and 230C, and internal heat loads; 0, 500, 700 and 1000 W. The results of the performance characteristics of the HCR indicate the encouraging enhancement of the AAC system compared to Hydrofluorocarbon refrigerant (HFC-R134a).