Ditulis pada tanggal 2 August 2017, oleh s3mesin, pada kategori Uncategorized


Air Conditioning (AC) has become the main accessories on the vehicle to improve driving comfort. However, as long as the AC system works by a vapor compression system, it will take power from the engine to drive the compressor and increases fuel consumption by 21-53%. Meanwhile, the LPG-fueled vehicle provides potential direct refrigeration from LPG phase changes in the vaporizer devices. This potential has not been utilized and lost through engine coolant.

Muji Setiyo, Doctoral Program of Mechanical Engineering, Faculty of Engineering Universitas Brawijaya (FTUB) see that potential and raised a dissertation with the title of Characteristics of Direct refrigeration from Evaporation Process of Liquefied Petroleum Gas (LPG) for Cooling Car Cabin. This study focuses on the characteristics of direct refrigeration (potential and actual) generated from the evaporation of the LPG for cooling the car cabin.

The study conducted by lecturer of Muhammadiyah University of Magelang is consists of four main phases. First, testing the composition of LPG by Gas Chromatography-Mass Spectrometry (GC-MS). Second, Simulation of energy delivery and potential cooling effect with data obtained from GC-MS. Third, validate the actual cooling effect on various of LPG mass flow rate and evaporation pressure. Finally, calculation of COP direct refrigeration (COPDR). The results of this study

The results of this study show that the composition of propane molecule and 2 methyl butane during tank emptying process is not constant. However, changes in LPG composition have no significant effect on the resulting cooling effect, as long as LPG flows into the fuel line (before expansion valve) as a liquid. The higher the evaporator vapor pressure in the evaporator and the greater the mass flow rate of LPG, the greater the cooling effect produced. However, the resulting cooling effect is non-linear with LPG mass flow rate due to the limitation of the heat transfer area of the evaporator.

The test results show the maximum cooling effect that can be generated is 1.2 kW. With the cooling load of passenger cars ranging from 3-6 kW, this means that the cooling effect of the LPG fuel stem contributes up to 40% to AC systems for vehicles with 3 kW of cooling load and 20% for vehicles with 6 kW of cooling load. In the case of direct refrigeration COPDR is calculated by comparing the effects of refrigeration by compression work to produce pressurized liquid LPG. COPDR decreases when LPG mass flow rate is increased and increases when evaporation pressure is increased.

“The concept of direct refrigeration on LPG-fueled vehicles is very promising to be developed as a hybrid system with AC system. In the next research I want to integrate it with the actual car air conditioning system,” said the son of Mardiyono and Sri Widayati.

In front of the Board of Examiners consisting of DrEng Mega Nur Sasongko ST MT, Agung Sugeng Widodo ST MT, and Prof. Ir Djoko Wahyu Karmiadji MSME PhD and the three Supervisors; Prof. Ir Sudjito Soeparman PhD, Dr. Slamet Wahyudi ST MT, DrEng Nurkholis Hamidi ST MEng., he successfully defended his dissertation and was awarded Doctorate of Mechanical Engineering with Cumlaude.

Present to give a speech on the open examination Tuesday (18/Jul/2017) that morning, Rector of Muhammadiyah University of Magelang, Ir. Eko Muh Widodo MT. “I would like to say welcome back to Dr. Muji in UnMuh Magelang Automotive Engine Study Program as the youngest Doctor on campus,” he said proudly. (mic)