Experiment, Lead Acid Battery, Automotive HVAC, COP.
In most of the Automotive Air Conditioning Systems (AACSs) though the compressor is powered by the car engine, the evaporator blower and the condenser fan are run by an alternator. Further, this alternator is powered from engine shaft. If there is any fault in the alternator that must drop the output voltage. This variation in output voltage can be achieved from a car battery by regulating its charging current. Owing to this, a stationary test rig for an AACS is developed with all actual automotive components coupled with a large number of sensors and additional accessories. However, the present investigation is restricted only to its air conditioning system, the alternator is replaced by a 12 volt lead acid car battery (capacity: 36 Ah) to invigorate the maneuvering of compressor clutch engagement and disengagement as well, empowerment of the prime movers. Now, a continuous monitoring of the system performance is done at different battery charge level. A DC power source is used to keep the battery voltage constant in different levels by varying the charging current. Further, in each battery charge level tests are conducted at three different blower speeds by regulating the existing toggle switch of the automobile. It is observed that the evaporator blower and the condenser fan speeds reduces continuously with the discharging of the storage battery, resulting a certain drop in air flow rate across the heat exchangers. Hence, the discharge pressure and the temperature increases due to lack of proper cooling across the condenser. Here, the continuous monitoring of the battery discharge voltage and its impact on the deterioration on the system cooling capacity, compression work and the COP are reported.