BITZER Kühlmaschinenbau GmbH
BITZER Kühlmaschinenbau GmbH
Air Conditioning in Rail Vehicles: Increased Comfort, Higher Energy Efficiency and Lower Operating Costs
This article first appeared in the Railway-News magazine, Issue 3 2024.
BITZER’s VARISTEP Solution
Energy-efficient operation of rail vehicles reduces operating costs, which also applies to its components. BITZER, has always developed and optimised its products with a focus on energy efficiency. To further reduce energy costs, BITZER ECOLINE compressors can be equipped with mechanical capacity regulators, called VARISTEP, to improve the overall system efficiency. The VARISTEP capacity control is suitable for use with a variety of refrigerants, including HFC and HFO refrigerants and natural refrigerant such as R290 (propane) and R744 (CO2).
Capacity Control for Increased Energy Savings
VARISTEP mechanical capacity control enables fine capacity adjustment for reciprocating compressors to effortlessly accommodate changing operating conditions. The extensive control range of around 25 to 100 per cent allows for outstanding full and part load efficiency and thus improves the efficiency of the entire air conditioning system. As a result, the annual operating costs associated with railway cooling and air conditioning systems are much lower than with conventional systems featuring hot gas bypass control.
The following diagrams reveal significant seasonal energy savings, calculated on the basis of a typical air conditioning system in operation on a suburban train in Central Europe. The diagram compares two identical refrigerating circuits operated with R290 – one with VARISTEP and the other with hot gas bypass. Different cooling loads and operating hours were observed over a period of twelve months. Where part load operation is frequent, energy savings can be as high as 40 per cent for compressor operation alone.
