Numerical Modeling Study of Air Flow Distribution in HVAC General Arrangements for Passenger Car of Indonesia High Speed Train Muhammad Penta Helios, Himawan Sutriyanto, Riki Jaka Komara, Andhy Muhammad Fathoni, Bhakti Nuryadin, Achmad Maswan, Kanon Prabandaru Sumarah, Bambang Teguh Prasetyo, Hariyotejo Pujowidodo, IGA Uttariyani, Hari Setiapraja
Center of Technology for Thermodynamics, Engines and Propulsion (BT2MP)
Puspiptek Area, Building#230, Setu,
South Tangerang, Banten, Indonesia 15314
Abstract
In contributing to the development of the Indonesian high-speed train on the Jakarta-Surabaya route, the design stage of the HVAC prototype using a vapor compression system with refrigerant R407C has been completed to meet the thermal comfort of the passenger cabin coach. The design comprised the calculation of the cooling load, the thermodynamic cycle of the system, the air cooling process, and the design of the main system components in the General Arrangement embed saloon integration unit mounted on the carbody. To obtain a GA design, according to the interior dimensions of the available space, it is necessary to conduct a numerical modeling study of the airflow distribution of the HVAC unit room, in order to obtain the characteristics of the supply air and the effective condenser cooling air.
A cubical space sized 2800x1900x600 mm, with solid geometry boundaries of enclosed walls, compartments, and system components, was discretized into the computational domain. Pressure boundary conditions were used as the parameters of airflow inlet and outlet. Heat exchanger and filter components were modeled as porous media, and flow was assumed steady, ideal gas fluid, and taking turbulence model k-epsilon as the governing equation for flow physics transport. Some aspects of the availability of unit space sizes, geometry and dimension of system components, space configuration for the sides of fresh, return, supply, and exhaust air ducts, as well as work parameters according to the results of calculations, were taken as input parameters in modeling.
Based on the analysis of the results of the HVAC unit space configuration modeling, it was found that the placement of the air sides in the mixing, supply, and condenser compartments, according to the work parameters that meet the design, greatly determined the characteristics of fluid flow, especially pressure distribution and flow recirculation. The flow energy loss due to pressure drop affects the energy consumption of the
