Environmentally friendly air conditioning for trains

Abstract

Current air-conditioning systems for railway vehicles predominantly use fluorinated refrigerants, which will be phased down in the coming years because of their damaging impact on the climate. Motivated by the need to implement environmentally friendly technologies that will be available for the long term for the air conditioning of passenger trains, Liebherr and Deutsche Bahn conducted a comparison of the annual energy consumption and the Total Cost of Ownership (TCO) of railway heating, ventilation, and air-conditioning systems (HVAC) using air and R-134a as refrigerants. Systems in operation and advanced systems were both assessed. Measurement data and model calculations obtained from systems in operation formed the basis for evaluation. For the average primary annual energy consumption for cooling, the air-cycle systems, which use air as refrigerant, had savings of 16% and 28%, respectively, compared to the R-134a systems that were considered. The higher investment costs of air-cycle systems are compensated by lower operating costs, particularly lower energy costs, and by lower maintenance costs, so that air-cycle systems have the advantage in terms of economic efficiency. As a result, air-cycle systems are an environmentally friendly, economical and reliable solution to the refrigerant issue. Quelle: Forschungsbericht

Today's railway air-conditioning systems cool primarily with fluorinated refrigerants, which have had to be scaled back step by step since 2016 due to their climate-damaging effect. Air-assisted air-conditioning systems, so-called air-cycle systems, use compressed outside air for cooling, so they do not require any fluorinated refrigerants. It has now also been proven that these air conditioning systems, which have been operating in trains for some time, are an environmentally friendly and economical solution to the refrigerant problem. For this purpose, the data from a two-year field data measurement in an Intercity Express were evaluated with regard to energy consumption and the life cycle costs of these air conditioners were determined. Air-cycle systems have an average annual cooling energy requirement of up to 28% less than conventional R134a systems.