rapid test method for evaluation of thermo-technical condition of non-traction rolling stock car bodies

Reduction of energy use and polluting emissions of engines and is one of the challenges for ecological balance. for achieving optimal power-to-weight ratio of railway transport, rapidly developing special vehicles (svs) equipped with power generating systems are considered as ambitious ones. svs include refrigerator, passenger, and multiple unit cars. optimization of energy consumed by svs’ heating and climatic installations helps minimize polluting emissions. variable-speed drive, energy saving additives are commonly used to reduce energy consumption. however, expected results can be achieved only by compliance of svs’ car bodies to the thermo-technical standards, regular checks of total heat transfer coefficient к (w/sqm*к) by thermo-technical tests. equilibrium method is internationally used for that: svs are placed into homoeothermic environment, and their car bodies are heated from the inside by thermal source of certain capacity to the moment when air temperature stops rising and remains stable. obtained air derivative represents equilibrium thermal condition; then k value is calculated. however, tests for calculation of k value are labor and time consuming and imply more 72 idle hours for tested svs. a non-equilibrium method as faster process is proposed, which is calculation of k using the data obtained after first 11 hours of tests. air heating process comprises irregular and regular phases. difference between the two is in the heating rate behavior. during the initial period, temperature ratio change pace dθ/dτ goes in accordance with equation: dθ/dτ = θ^1-b/a (1), where а and в are constant coefficients. 1-b to be read as power of θ. then, irregular phase succeeds by a regular one in the point of contact of curve (1) and straight line (2). then the pace is defined by heat balance equation: dθ/dτ = p/w-khθ/w (2), where: θ -air temperature differential inside and outside of svs; τ -time; dθ/dτ -temperature ratio change pace; р -heat source output; w -water equivalent of svs car bodies; к -total heat transfer coefficient of car body; н -size of heat-exchange surface of svs car bodies. simultaneous solution of these equations gives an expression to calculate k value. this method allows conducting tests without affecting accuracy of values for k. by now, a software package that helps increasing efficiency of test facilities by 2.5 times is developed. thermo-technical condition of sv car bodies is totally and continuously controlled, which is a prerequisite for forecast and assessment of carbon dioxide emission volumes.