高铁一坐就困？最新回应

Core Viewpoint - The reported CO2 concentration levels in high-speed train carriages exceed the standard limit of 1000ppm, but the standards applicable to passenger trains differ from those for buildings, with higher acceptable limits in place for rail vehicles [1][2]. Group 1: Standards and Regulations - The CO2 concentration control standard for passenger trains in China is defined by TB/T 3493-2017, which allows a maximum of 2500ppm under normal operating conditions [1]. - European standards EN13129-2016 set the limit for CO2 concentration in passenger trains at 5000ppm [1]. - The reported values were compared against GB 50736-2012, which is not applicable to passenger trains, as it pertains to indoor air quality in buildings [1]. Group 2: Air Quality Management in Trains - The train carriages are designed with a fully sealed body, and air exchange is managed entirely by the air conditioning ventilation system, providing over 15m³/h of fresh air per person [2]. - The air exchange rate in the train is between 6 to 12 times per hour, and a pressure protection system is in place [2]. - During operation in non-tunnel areas, CO2 concentration typically does not exceed 1500ppm; however, in tunnels, the system temporarily closes external air access to prevent ear discomfort, which may lead to a short-term increase in CO2 levels without health risks to passengers [2].