铁路专家：我国旅客列车二氧化碳浓度标准限值为不超过2500ppm

Core Viewpoint - The discussion regarding the carbon dioxide concentration in high-speed train carriages exceeding 1000ppm is addressed, clarifying that the standards for passenger trains differ from those for civil buildings [1] Group 1: Standards and Regulations - The carbon dioxide concentration control standard for passenger trains in China is based on TB/T 3493-2017, which sets the limit at 2500ppm under normal operating conditions, while European standards allow up to 5000ppm [1] - The reported passenger measurements reference GB 50736-2012, which is not applicable to passenger trains, as each country's standards are based on the unique characteristics of mobile transport equipment [1] Group 2: Air Quality Management in Trains - China's passenger trains, including high-speed trains, are designed to meet ventilation needs, ensuring continuous supply of fresh air and removal of waste gases, with parameters like air cleanliness and temperature uniformity meeting national railway standards [2] - High-speed trains utilize a ventilation system that includes pressure protection, with an average fresh air supply of over 15m³/h per person and air exchange rates of 6 to 12 times per hour [2] - During operation in non-tunnel sections, carbon dioxide levels typically do not exceed 1500ppm; however, in tunnels, pressure protection measures may temporarily increase CO2 levels due to the closure of external air passages [2]