Design and Fabrication of Novel Air Conditioning System in CNG Fitted Vehicles

Sana Ullah; Asad Ullah; Abdul Haseeb; Muhammad Adnan; Sayed Munib; Muhammad Zaid Bukhari

Authors

Sana Ullah Department of Mechanical Engineering, University of Engineering and Technology, Peshawar 25120, Pakistan
Asad Ullah Department of Mechanical Engineering, University of Engineering and Technology, Mardan 23200, Pakistan
Abdul Haseeb Department of Mechanical Engineering, University of Engineering and Technology, Mardan 23200, Pakistan
Muhammad Adnan Department of Mechanical Engineering, University of Engineering and Technology, Mardan 23200, Pakistan
Sayed Munib Department of Mechanical Engineering, University of Engineering and Technology, Mardan 23200, Pakistan
Muhammad Zaid Bukhari Department of Mechanical Engineering, University of Engineering and Technology, Peshawar 25120, Pakistan

Keywords:

Traditional Air Conditioning, Novel Air Conditioning, Compressed Natural Gas (CNG), Joule-Thomson effect, Fuel Consumption

Abstract

This paper presents a novel air conditioning system for Compressed Natural Gas (CNG)-fitted vehicles that overcomes the high fuel consumption of conventional belt-driven compressors. The system utilizes the Joule–Thomson effect of CNG expansion to generate cooling, captured through a heat exchanger and circulated via a blower, without adding engine load. CNG consumption was measured by recording the initial and final tank pressures and calculating the consumed gas mass based on tank volume and CNG density. Emissions were measured using a gas flow analyzer, with sensors placed in the vehicle’s silencer. Tests were conducted under identical conditions for both the conventional and the proposed air conditioning systems. The main objective of this project was to get a fuel-free air conditioning system in CNG-fitted vehicles. Experimental results show a significant cabin temperature drop to 11°C (284.15K) in 14 minutes (readings were noted by using digital multi meter having temperature sensor), improved fuel economy up to 25% as compared to conventional air conditioning system, and reduced emissions of CO₂ about 55% and CO about 30% (emissions reading were noted by using kane-458s gas flow analyzer). Car Consumption has been calculated by an indirect gravimetric (pressure-density-based) method used to estimate CNG fuel consumption. The findings confirm that the system is a technically feasible, low-cost, and sustainable alternative to conventional AC units for CNG vehicles, especially in hot climates.

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